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Sample records for endothelial repair capacity

  1. Variation in Base Excision Repair Capacity

    PubMed Central

    Wilson, David M.; Kim, Daemyung; Berquist, Brian R.; Sigurdson, Alice J.

    2010-01-01

    The major DNA repair pathway for coping with spontaneous forms of DNA damage, such as natural hydrolytic products or oxidative lesions, is base excision repair (BER). In particular, BER processes mutagenic and cytotoxic DNA lesions such as non-bulky base modifications, abasic sites, and a range of chemically distinct single-strand breaks. Defects in BER have been linked to cancer predisposition, neurodegenerative disorders, and immunodeficiency. Recent data indicate a large degree of sequence variability in DNA repair genes and several studies have associated BER gene polymorphisms with disease risk, including cancer of several sites. The intent of this review is to describe the range of BER capacity among individuals and the functional consequences of BER genetic variants. We also discuss studies that associate BER deficiency with disease risk and the current state of BER capacity measurement assays. PMID:21167187

  2. Extrarenal Progenitor Cells Do Not Contribute to Renal Endothelial Repair.

    PubMed

    Sradnick, Jan; Rong, Song; Luedemann, Anika; Parmentier, Simon P; Bartaun, Christoph; Todorov, Vladimir T; Gueler, Faikah; Hugo, Christian P; Hohenstein, Bernd

    2016-06-01

    Endothelial progenitor cells (EPCs) may be relevant contributors to endothelial cell (EC) repair in various organ systems. In this study, we investigated the potential role of EPCs in renal EC repair. We analyzed the major EPC subtypes in murine kidneys, blood, and spleens after induction of selective EC injury using the concanavalin A/anti-concanavalin A model and after ischemia/reperfusion (I/R) injury as well as the potential of extrarenal cells to substitute for injured local EC. Bone marrow transplantation (BMTx), kidney transplantation, or a combination of both were performed before EC injury to allow distinction of extrarenal or BM-derived cells from intrinsic renal cells. During endothelial regeneration, cells expressing markers of endothelial colony-forming cells (ECFCs) were the most abundant EPC subtype in kidneys, but were not detected in blood or spleen. Few cells expressing markers of EC colony-forming units (EC-CFUs) were detected. In BM chimeric mice (C57BL/6 with tandem dimer Tomato-positive [tdT+] BM cells), circulating and splenic EC-CFUs were BM-derived (tdT+), whereas cells positive for ECFC markers in kidneys were not. Indeed, most BM-derived tdT+ cells in injured kidneys were inflammatory cells. Kidneys from C57BL/6 donors transplanted into tdT+ recipients with or without prior BMTx from C57BL/6 mice were negative for BM-derived or extrarenal ECFCs. Overall, extrarenal cells did not substitute for any intrinsic ECs. These results demonstrate that endothelial repair in mouse kidneys with acute endothelial lesions depends exclusively on local mechanisms.

  3. Elevated Soluble Flt1 Inhibits Endothelial Repair in PR3-ANCA–Associated Vasculitis

    PubMed Central

    Le Roux, Sandrine; Pepper, Ruth J.; Dufay, Alexandre; Néel, Mélanie; Meffray, Emmanuelle; Lamandé, Noël; Rimbert, Marie; Josien, Régis; Hamidou, Mohamed; Hourmant, Maryvonne; Cook, H. Terence; Charreau, Béatrice; Larger, Etienne; Salama, Alan D.

    2012-01-01

    Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis exhibits endothelial damage, but the capacity for vessel repair in this disorder is not well understood. Here, we observed a marked increase in serum levels of soluble Flt1 (sFlt1), a potent inhibitor of vascular endothelial growth factor, in patients with active ANCA-associated vasculitis compared with patients during remission and other controls. Serum levels of sFlt1 correlated with C5a, an anaphylatoxin released after complement activation. Serum from patients with acute ANCA-associated vasculitis disrupted blood flow in the chicken chorioallantoic membrane assay, suggesting an antiangiogenic effect. Preincubation with excess human vascular endothelial growth factor prevented this effect. Anti–proteinase-3 (PR3) mAb and serum containing PR3-ANCA from patients with active vasculitis both induced a significant and sustained release of sFlt1 from monocytes, whereas anti-myeloperoxidase (MPO) mAb or polyclonal antibodies did not. However, the serum containing polyclonal PR3-ANCA did not induce release of sFlt1 from cultured human umbilical vein endothelial cells. In summary, these data suggest that anti-PR3 antibodies, and to a much lesser extent anti-MPO antibodies, increase sFlt1 during acute ANCA-associated vasculitis, leading to an antiangiogenic state that hinders endothelial repair. PMID:22034638

  4. Base excision repair capacity in informing healthspan

    PubMed Central

    Brenerman, Boris M.; Illuzzi, Jennifer L.; Wilson, David M.

    2014-01-01

    Base excision repair (BER) is a frontline defense mechanism for dealing with many common forms of endogenous DNA damage, several of which can drive mutagenic or cell death outcomes. The pathway engages proteins such as glycosylases, abasic endonucleases, polymerases and ligases to remove substrate modifications from DNA and restore the genome back to its original state. Inherited mutations in genes related to BER can give rise to disorders involving cancer, immunodeficiency and neurodegeneration. Studies employing genetically defined heterozygous (haploinsufficient) mouse models indicate that partial reduction in BER capacity can increase vulnerability to both spontaneous and exposure-dependent pathologies. In humans, measurement of BER variation has been imperfect to this point, yet tools to assess BER in epidemiological surveys are steadily evolving. We provide herein an overview of the BER pathway and discuss the current efforts toward defining the relationship of BER defects with disease susceptibility. PMID:25355293

  5. METABOLIC CAPACITY REGULATES IRON HOMEOSTATIS IN ENDOTHELIAL CELLS

    EPA Science Inventory

    The sensitivity of endothelial cells to oxidative stress and the high concentrations of iron in mitochondria led us to test the hypotheses that (1) changes in respiratory capacity alter iron homeostasis, and (2) lack of aerobic metabolism decreases labile iron stores and attenuat...

  6. The sulfated polysaccharide fucoidan rescues senescence of endothelial colony-forming cells for ischemic repair.

    PubMed

    Lee, Jun Hee; Lee, Sang Hun; Choi, Sung Hyun; Asahara, Takayuki; Kwon, Sang-Mo

    2015-06-01

    The efficacy of cell therapy using endothelial colony-forming cells (ECFCs) in the treatment of ischemia is limited by the replicative senescence of isolated ECFCs in vitro. Such senescence must therefore be overcome in order for such cell therapies to be clinically applicable. This study aimed to investigate the potential of sulfated polysaccharide fucoidan to rescue ECFCs from cellular senescence and to improve in vivo vascular repair by ECFCs. Fucoidan-preconditioning of senescent ECFCs was shown by flow cytometry to restore the expression of functional ECFC surface markers (CD34, c-Kit, VEGFR2, and CXCR4) and stimulate the in vitro tube formation capacity of ECFCs. Fucoidan also promoted the expression of cell cycle-associated proteins (cyclin E, Cdk2, cyclin D1, and Cdk4) in senescent ECFCs, significantly reversed cellular senescence, and increased the proliferation of ECFCs via the FAK, Akt, and ERK signaling pathways. Fucoidan was found to enhance the survival, proliferation, incorporation, and endothelial differentiation of senescent ECFCs transplanted in ischemic tissues in a murine hind limb ischemia model. Moreover, ECFC-induced functional recovery and limb salvage were markedly improved by fucoidan pretreatment of ECFCs. To our knowledge, the findings of our study are the first to demonstrate that fucoidan enhances the neovasculogenic potential of ECFCs by rescuing them from replicative cellular senescence. Pretreatment of ECFCs with fucoidan may thus provide a novel strategy for the application of senescent stem cells to therapeutic neovascularization.

  7. Augmenting endothelial repair in diabetes: role of bone marrow-derived cells.

    PubMed

    Gilbert, Richard E

    2013-10-01

    Endothelial loss, a consequence of both higher rates of apoptosis and diminished repair, is a major factor in the pathogenesis of diabetes complications. Although the repair process previously was viewed to arise primarily from the proliferation and migration of neighbouring endothelial cells, it now has become evident that certain bone marrow-derived cells contribute substantially to this process. Unfortunately, both the number and function of such cells are reduced in diabetes. Here, we first review the effects of current therapies on angiogenic bone marrow-derived cells and then explore future strategies to augment their number and function, aiming to reduce both the microvascular and macrovascular complications of diabetes.

  8. Endothelial Activation and Repair During Hantavirus Infection: Association with Disease Outcome

    PubMed Central

    Connolly-Andersen, Anne-Marie; Thunberg, Therese; Ahlm, Clas

    2014-01-01

    Background.  Endothelial activation and dysfunction play a central role in the pathogenesis of sepsis and viral hemorrhagic fevers. Hantaviral disease is a viral hemorrhagic fever and is characterized by capillary dysfunction, although the underlying mechanisms for hantaviral disease are not fully elucidated. Methods.  The temporal course of endothelial activation and repair were analyzed during Puumala hantavirus infection and associated with disease outcome and a marker for hypoxia, insulin-like growth factor binding protein 1 (IGFBP-1). The following endothelial activation markers were studied: endothelial glycocalyx degradation (syndecan-1) and leukocyte adhesion molecules (soluble vascular cellular adhesion molecule 1, intercellular adhesion molecule 1, and endothelial selectin). Cytokines associated with vascular repair were also analyzed (vascular endothelial growth factor, erythropoietin, angiopoietin, and stromal cell-derived factor 1). Results.  Most of the markers we studied were highest during the earliest phase of hantaviral disease and associated with clinical and laboratory surrogate markers for disease outcome. In particular, the marker for glycocalyx degradation, syndecan-1, was significantly associated with levels of thrombocytes, albumin, IGFBP-1, decreased blood pressure, and disease severity. Conclusions.  Hantaviral disease outcome was associated with endothelial dysfunction. Consequently, the endothelium warrants further investigation when designing future medical interventions. PMID:25734100

  9. Pulmonary metastasis after bleomycin-induced endothelial injury and repair

    SciTech Connect

    Adamson, I.Y.R.; Young, L.; Orr, F.W.

    1986-03-01

    Injury to the endothelial barrier is thought to enhance the localization and metastasis of circulating tumor cells. This hypothesis was tested by inducing pulmonary endothelial injury in C57bl/6 mice by injecting a single IV dose of bleomycine (120 mg/kg). After 5 days, severe endothelial injury was demonstrated by morphology and by increased levels of protein in lung lavage fluid. When /sup 131/I-iododeoxyuridine labeled syngeneic fibrosarcoma cells were injected IV at this time, a 9 fold increase in their localization was detected 24 hrs later in bleomycin-treated lungs compared to saline controls. By EM, tumor cells were observed at sites of denuded vascular basement membrane. There was also a significant increase in subsequent gross metastases and percentage of lung occupied by tumor in the bleomycin group. Animals examined 10 days after bleomycin showed less endothelial damage and a smaller increase in tumor cell localization and metastases. At 21 days, when endothelial structure and alveolar protein levels had returned to normal, and at 6 weeks, when there was focal fibrosis, no increase in tumor cell localization or metastases was found. It is concluded that damage to the pulmonary endothelium is a key factor in enhancing the trapping of circulating tumor cells and increasing metastatic tumor growth.

  10. DNA damage repair and genetic polymorphisms: Assessment of individual sensitivity and repair capacity

    SciTech Connect

    Cornetta, Tommaso; Festa, Fabiola; Testa, Antonella; Cozzi, Renata Prof. . E-mail: cozzi@uniroma3.it

    2006-10-01

    Purpose: To study the repair capacity after X-ray irradiation in human peripheral blood cells of healthy subjects, in relation to their genotypes. Methods and Materials: The peripheral blood of 50 healthy subjects was irradiated in vitro with 2 Gy of X rays and the induced DNA damage was measured by Comet assay immediately after irradiation. DNA repair was detected by analyzing the cells at defined time intervals after the exposure. Furthermore, all subjects were genotyped for XRCC1, OGG1, and XPC genes. Results: After X-ray irradiation, persons bearing XRCC1 homozygous variant (codon 399) genotype exhibited significantly lower Tail DNA values than those bearing wild-type and heterozygous genotypes. These results are also confirmed at 30 and 60 min after irradiation. Furthermore, XPC heterozygous subjects (variant codon 939) showed lower residual DNA damage 60 min after irradiation compared with wild-type and homozygous genotypes. Conclusion: The results of the present study show that polymorphisms in DNA repair genes could influence individual DNA repair capacity.

  11. Prohibitin-1 maintains the angiogenic capacity of endothelial cells by regulating mitochondrial function and senescence

    PubMed Central

    Schleicher, Michael; Shepherd, Benjamin R.; Suarez, Yajaira; Fernandez-Hernando, Carlos; Yu, Jun; Pan, Yong; Acevedo, Lisette M.; Shadel, Gerald S.; Sessa, William C.

    2008-01-01

    Prohibitin 1 (PHB1) is a highly conserved protein that is mainly localized to the inner mitochondrial membrane and has been implicated in regulating mitochondrial function in yeast. Because mitochondria are emerging as an important regulator of vascular homeostasis, we examined PHB1 function in endothelial cells. PHB1 is highly expressed in the vascular system and knockdown of PHB1 in endothelial cells increases mitochondrial production of reactive oxygen species via inhibition of complex I, which results in cellular senescence. As a direct consequence, both Akt and Rac1 are hyperactivated, leading to cytoskeletal rearrangements and decreased endothelial cell motility, e.g., migration and tube formation. This is also reflected in an in vivo angiogenesis assay, where silencing of PHB1 blocks the formation of functional blood vessels. Collectively, our results provide evidence that PHB1 is important for mitochondrial function and prevents reactive oxygen species–induced senescence and thereby maintains the angiogenic capacity of endothelial cells. PMID:18195103

  12. Longevity and resistance to stress correlate with DNA repair capacity in Caenorhabditis elegans.

    PubMed

    Hyun, Moonjung; Lee, Jihyun; Lee, Kyungjin; May, Alfred; Bohr, Vilhelm A; Ahn, Byungchan

    2008-03-01

    DNA repair is an important mechanism by which cells maintain genomic integrity. Decline in DNA repair capacity or defects in repair factors are thought to contribute to premature aging in mammals. The nematode Caenorhabditis elegans is a good model for studying longevity and DNA repair because of key advances in understanding the genetics of aging in this organism. Long-lived C. elegans mutants have been identified and shown to be resistant to oxidizing agents and UV irradiation, suggesting a genetically determined correlation between DNA repair capacity and life span. In this report, gene-specific DNA repair is compared in wild-type C. elegans and stress-resistant C. elegans mutants for the first time. DNA repair capacity is higher in long-lived C. elegans mutants than in wild-type animals. In addition, RNAi knockdown of the nucleotide excision repair gene xpa-1 increased sensitivity to UV and reduced the life span of long-lived C. elegans mutants. These findings support that DNA repair capacity correlates with longevity in C. elegans.

  13. Influence of calorie reduction on DNA repair capacity of human peripheral blood mononuclear cells.

    PubMed

    Matt, Katja; Burger, Katharina; Gebhard, Daniel; Bergemann, Jörg

    2016-03-01

    Caloric restrictive feeding prolongs the lifespan of a variety of model organisms like rodents and invertebrates. It has been shown that caloric restriction reduces age-related as well as overall-mortality, reduces oxidative stress and influences DNA repair ability positively. There are numerous studies underlining this, but fewer studies involving humans exist. To contribute to a better understanding of the correlation of calorie reduction and DNA repair in humans, we adapted the host cell reactivation assay to an application with human peripheral blood mononuclear cells. Furthermore, we used this reliable and reproducible assay to research the influence of a special kind of calorie reduction, namely F. X. Mayr therapy, on DNA repair capacity. We found a positive effect in all persons with low pre-existing DNA repair capacity. In individuals with normal pre-existing DNA repair capacity, no effect on DNA repair capacity was detectable. Decline of DNA repair, accumulation of oxidative DNA damages, mitochondrial dysfunction, telomere shortening as well as caloric intake are widely thought to contribute to aging. With regard to that, our results can be considered as a strong indication that calorie reduction may support DNA repair processes and thus contribute to a healthier aging.

  14. Working memory capacity and self-repair behavior in first and second language oral production.

    PubMed

    Mojavezi, Ahmad; Ahmadian, Mohammad Javad

    2014-06-01

    This study explores the relationship between working memory capacity and self-repair behavior in first (L1) and second language (L2) oral production. 40 Iranian intermediate EFL learners participated in this study. Their working memory capacity was measured via a version of listening span test. The participants performed two oral narrative tasks, one in their L2 (English) and one in their L1 (Farsi). Then, they were asked to listen to their own narrations and comment on the repairs they made in their speech. Self-repairs were analyzed and categorized taking into account the participants' stimulated recall comments. Results of the analyses pointed to positive correlations between the participants' working memory capacity and self-repairs in the L2 but not in the L1. Also, results revealed that whereas in the case of L1, the participants effectuated different-information and appropriacy repairs more than error-repairs, in the case of L2 more error-repairs were made. PMID:23709259

  15. Nuclear Countermeasure Activity of TP508 Linked to Restoration of Endothelial Function and Acceleration of DNA Repair

    PubMed Central

    Olszewska-Pazdrak, Barbara; McVicar, Scott D.; Rayavara, Kempaiah; Moya, Stephanie M.; Kantara, Carla; Gammarano, Chris; Olszewska, Paulina; Fuller, Gerald M.; Sower, Laurie E.; Carney, Darrell H.

    2016-01-01

    There is increasing evidence that radiation-induced damage to endothelial cells and loss of endothelial function may contribute to both acute radiation syndromes and long-term effects of whole-body nuclear irradiation. Therefore, several drugs are being developed to mitigate the effects of nuclear radiation, most of these drugs will target and protect or regenerate leukocytes and platelets. Our laboratory has demonstrated that TP508, a 23-amino acid thrombin peptide, activates endothelial cells and stem cells to revascularize and regenerate tissues. We now show that TP508 can mitigate radiation-induced damage to endothelial cells in vitro and in vivo. Our in vitro results demonstrate that human endothelial cells irradiation attenuates nitric oxide (NO) signaling, disrupts tube formation and induces DNA double-strand breaks (DSB). TP508 treatment reverses radiation effects on NO signaling, restores tube formation and accelerates the repair of radiation-induced DSB. The radiation-mitigating effects of TP508 on endothelial cells were also seen in CD-1 mice where systemic injection of TP508 stimulated endothelial cell sprouting from aortic explants after 8 Gy irradiation. Systemic doses of TP508 that mitigated radiation-induced endothelial cell damage, also significantly increased survival of CD-1 mice when injected 24 h after 8.5 Gy exposure. These data suggest that increased survival observed with TP508 treatment may be due to its effects on vascular and microvascular endothelial cells. Our study supports the usage of a regenerative drug such as TP508 to activate endothelial cells as a countermeasure for mitigating the effects of nuclear radiation. PMID:27388041

  16. Endothelial function in obstructive sleep apnea.

    PubMed

    Atkeson, Amy; Yeh, Susie Yim; Malhotra, Atul; Jelic, Sanja

    2009-01-01

    Untreated obstructive sleep apnea (OSA) is an independent risk factor for hypertension, myocardial infarction, and stroke. The repetitive hypoxia/reoxygenation and sleep fragmentation associated with OSA impair endothelial function. Endothelial dysfunction, in turn, may mediate increased risk for cardiovascular diseases. Specifically, in OSA, endothelial nitric oxide availability and repair capacity are reduced, whereas oxidative stress and inflammation are enhanced. Treatment of OSA improves endothelial vasomotor tone and reduces inflammation. We review the evidence and possible mechanisms of endothelial dysfunction as well as the effect of treatment on endothelial function in OSA.

  17. EGF and PGE2: effects on corneal endothelial cell migration and monolayer spreading during wound repair in vitro.

    PubMed

    Joyce, N C; Joyce, S J; Powell, S M; Meklir, B

    1995-07-01

    In vivo repair of the adult human corneal endothelium occurs mainly by movement of cells into the wound defect rather than by cell division. Two forms of cell movement contribute to endothelial wound repair: migration of individual cells into the defect and spreading of the confluent monolayer into the wound area. This laboratory has developed a tissue culture model using rabbit corneal endothelial cells pretreated with the mitotic inhibitor 5-fluorouracil to mimic the relatively amitotic state of human corneal endothelium in vivo. This model permits study of the effects of growth factors and other agents on individual cell migration and monolayer spreading in response to wounding. mRNA for epidermal growth factor (EGF) and its receptor has been detected in cultured corneal endothelial cells and EGF receptors have been detected on human corneal endothelial cells in situ, suggesting that this growth factor may act in an autocrine manner. Prostaglandin E2 (PGE2) is synthesized by cultured corneal endothelial cells and is present in relatively high quantity in aqueous humor in response to corneal wounding and to inflammation in the anterior chamber. Although corneal endothelial cells may be exposed to both EGF and PGE2, little is known about their effects on monolayer repair. The current study compared the effects of PGE2 alone, EGF alone, and both agents in combination on individual cell migration and monolayer spreading using the wound model system and also determined the effect of EGF on PGE2 secretion using a commercial immunoassay. A 15 min exposure of wounded cultures to exogenous PGE2 stimulated individual cell migration and suppressed monolayer spreading.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7587307

  18. Vascular Endothelial Growth Factor Promotes Fibrosis Resolution and Repair in Mice

    PubMed Central

    Yang, Liu; Kwon, Junghee; Popov, Yury; Gajdos, Gabriella B.; Ordog, Tamas; Brekken, Rolf A.; Mukhopadhyay, Debabrata; Schuppan, Detlef; Bi, Yan; Simonetto, Douglas; Shah, Vijay H.

    2014-01-01

    Background & Aims Vascular endothelial growth factor (VEGF)—induced angiogenesis is implicated in fibrogenesis and portal hypertension. However, the function of VEGF in fibrosis resolution has not been explored. Methods We developed a cholecystojejunostomy procedure to reconstruct biliary flow after bile duct ligation in C57BL/6 mice to generate a model of fibrosis resolution. These mice were then given injections of VEGF-neutralizing (mcr84) or control antibodies, and other mice received an adenovirus that expressed mouse VEGF or a control vector. The procedure was also performed on macro-phage fas-induced apoptosis mice, in which macrophages can be selectively depleted. Liver and blood samples were collected and analyzed in immunohistochemical, morphometric, vascular permeability, real-time polymerase chain reaction, and flow cytometry assays. Results VEGF-neutralizing antibodies prevented development of fibrosis but also disrupted hepatic tissue repair and fibrosis resolution. During fibrosis resolution, VEGF inhibition impaired liver sinusoidal permeability, which was associated with reduced monocyte migration, adhesion, and infiltration of fibrotic liver. Scar-associated macrophages contributed to this process by producing the chemokine (C-X-C motif) ligand 9 and matrix metalloproteinase 13. Resolution of fibrosis was impaired in macrophage fas-induced apoptosis mice but increased after overexpression of chemokine (C-X-C motif) ligand 9. Conclusions In a mouse model of liver fibrosis resolution, VEGF promoted fibrogenesis, but was also required for hepatic tissue repair and fibrosis resolution. We observed that VEGF regulates vascular permeability, monocyte infiltration, and scar-associated macrophages function. PMID:24503129

  19. Loss of DNA repair capacity during successive subcultures of primary rat fibroblasts

    PubMed Central

    1977-01-01

    Cultures of fibroblasts from newborn rats and successive subcultures of these cells were treated with 4-nitroquinoline-1-oxide to induce DNA repair. DNA from the cultures was examined by velocity sedimentation in alkaline sucrose gradients immediately after drug treatment and after a post-treatment incubation period of 3 h. Early passage cells were able to repair the damage that appeared as single strand breaks, however, by the seventh subculture this activity was not apparent. Measurements of repair synthesis showed a partial loss of this capacity with successive subculture. The results fit a model in which 4NQO causes two kinds of DNA modification, one of which is alkali labile and appears as a single- strand break. Both modifications are subject to excision repair, but each is recognized initially by a specific endonuclease. In the late passage cells, the endonuclease specific for the alkali labile modification is absent. PMID:407232

  20. Right Ventricular Mass is Associated with Exercise Capacity in Adults with Repaired Tetralogy of Fallot.

    PubMed

    O'Meagher, Shamus; Seneviratne, Martin; Skilton, Michael R; Munoz, Phillip A; Robinson, Peter J; Malitz, Nathan; Tanous, David J; Celermajer, David S; Puranik, Rajesh

    2015-08-01

    The relationship between exercise capacity and right ventricular (RV) structure and function in adult repaired tetralogy of Fallot (TOF) is poorly understood. We therefore aimed to examine the relationships between cardiac MRI and cardiopulmonary exercise test variables in adult repaired TOF patients. In particular, we sought to determine the role of RV mass in determining exercise capacity. Eighty-two adult repaired TOF patients (age at evaluation 26 ± 10 years; mean age at repair 2.5 ± 2.8 years; 23.3 ± 7.9 years since repair; 53 males) (including nine patients with tetralogy-type pulmonary atresia with ventricular septal defect) were prospectively recruited to undergo cardiac MRI and cardiopulmonary exercise testing. As expected, these repaired TOF patients had RV dilatation (indexed RV end-diastolic volume: 153 ± 43.9 mL/m(2)), moderate-severe pulmonary regurgitation (pulmonary regurgitant fraction: 33 ± 14 %) and preserved left (LV ejection fraction: 59 ± 8 %) and RV systolic function (RV ejection fraction: 51 ± 7 %). Exercise capacity was near-normal (peak work: 88 ± 17 % predicted; peak oxygen consumption: 84 ± 17 % predicted). Peak work exhibited a significant positive correlation with RV mass in univariate analysis (r = 0.45, p < 0.001) and (independent of other cardiac MRI variables) in multivariate analyses. For each 10 g higher RV mass, peak work was 8 W higher. Peak work exhibits a significant positive correlation with RV mass, independent of other cardiac MRI variables. RV mass measured on cardiac MRI may provide a novel marker of clinical progress in adult patients with repaired TOF. PMID:25795311

  1. No Effect of Caloric Restriction or Exercise on Radiation Repair Capacity

    PubMed Central

    Habermann, Nina; Makar, Karen W.; Abbenhardt, Clare; Xiao, Liren; Wang, Ching-Yun; Utsugi, Heidi K.; Alfano, Catherine M.; Campbell, Kristin L.; Duggan, Catherine; Foster-Schubert, Karen E.; Mason, Caitlin E.; Imayama, Ikuyo; Blackburn, George L.; Potter, John D.; McTiernan, Anne; Ulrich, Cornelia M.

    2015-01-01

    Introduction Maintenance of normal weight and higher levels of physical activity are associated with a reduced risk of several types of cancer. As genomic instability is regarded as a hallmark of cancer development, one proposed mechanism is improvement of DNA repair function. We investigated links between dietary weight loss, exercise, and strand break rejoining in an ancillary study to a randomized-controlled trial. Methods Overweight/obese postmenopausal women (n=439) were randomized to: a) reduced-calorie weight-loss diet (“diet” n=118); b) moderate-to-vigorous intensity aerobic exercise (“exercise” n=117); c) a combination (“diet+exercise” n=117); or d) control (n=87). The reduced-calorie diet had a 10% weight-loss goal. The exercise intervention consisted of 45 minutes of moderate-to-vigorous aerobic activity 5 days/week for 12 months. DNA repair capacity was measured in a subset of 226 women at baseline and 12 months, from cryopreserved peripheral mononuclear cells using the Comet assay. Anthropometric and body composition measures were performed at baseline and 12 months. Results DNA repair capacity did not change significantly with any of the 12 month interventions compared to control; there were also no significant changes when stratified by changes in body composition or aerobic fitness (VO2max). At baseline, DNA repair capacity was positively associated with weight, BMI, and fat mass (r=0.20, p=0.003; r=0.19, p=0.004; r=0.13, p=0.04, respectively) and inversely with lean body mass (r=-0.14, p=0.04). Conclusion In conclusion, DNA repair capacity did not change with dietary weight loss or exercise interventions in postmenopausal women within a period of 12 months. Other assays that capture different facets of DNA repair function may be needed. PMID:25160845

  2. β-Cyclodextrin-Linked Polyethylenimine Nanoparticles Facilitate Gene Transfer and Enhance the Angiogenic Capacity of Mesenchymal Stem Cells for Wound Repair and Regeneration.

    PubMed

    Peng, Li-Hua; Wei, Wei; Shan, Ying-Hui; Zhang, Tian-Yuan; Zhang, Chen-Zhen; Wu, Jia-He; Yu, Lian; Lin, Jun; Liang, Wen-Quan; Khang, Gilson; Gao, Jian-Qing

    2015-04-01

    Repair of deep wounds by cell transplantation strongly depends on angiogenesis and on the regeneration of skin and appendages. In this study, plasmid DNA encoding vascular endothelial growth factor-165 (VEGF-165) was transduced into bone-marrow mesenchymal stem cells (MSCs) using a nonviral vector, β-cyclodextrin-linked polyethylenimine, to enhance angiogenic capacity. The effects of MSCs administered by intradermal injection or transplantation on wound closure were compared in a full-thickness excision wound model. The results showed that the MSC-seeded sponge had significantly stronger acceleration in wound closure than the MSC injection. The effects on wound repair and regeneration of transplanted MSCs and pDNA-VEGF1 65-transfected MSCs (TMSCs) with gelatin/β-tricalcium phosphate scaffold were also investigated. Compared with MSC transplantation, TMSC transplantation showed higher efficacy in stimulating wound closure, promoting dermal collagen synthesis and regulating the deposition of newly formed collagen. In addition, the angiogenic capacity of the TMSCs was higher than that of the MSCs. The results indicate that the nonviral genetic engineering of the MSCs is a promising strategy to enhance the angiogenic capacity of MSCs for wound repair and angiogenesis. Functional gene-activated MSCs may be used as cost-effective and accessible seed cells for skin tissue engineering and as novel carriers for wound gene therapy. PMID:26310074

  3. The effect of aging on the DNA damage and repair capacity in 2BS cells undergoing oxidative stress.

    PubMed

    Wang, Jin-Ling; Wang, Pei-Chang

    2012-01-01

    Aging is associated with a reduction in the DNA repair capacity under oxidative stress. However, whether the DNA damage and repair capacity can be a biomarker of aging remains controversial. In this study, we demonstrated two cause-and-effect relationships, the one is between the DNA damage and repair capacity and the cellular age, another is between DNA damage and repair capacity and the level of oxidative stress in human embryonic lung fibroblasts (2BS) exposed to different doses of hydrogen peroxide (H2O2). To clarify the mechanisms of the age-related reduction in DNA damage and repair capacity, we preliminarily evaluated the expressions of six kinds of pivotal enzymes involved in the two classical DNA repair pathways. The DNA repair capacity was observed in human fibroblasts cells using the comet assay; the age-related DNA repair enzymes were selected by RT-PCR and then verified by Western blot in vitro. Results showed that the DNA repair capacity was negatively and linearly correlated with (i) cumulative population doubling (PD) levels only in the group of low concentration of hydrogen peroxide treatment, (ii) with the level of oxidative stress only in the group of young PD cells. The mRNA expression of DNA polymerase δ1 decreased substantially in senescent cells and showed negative linear-correlation with PD levels; the protein expression level was well consistent with the mRNA level. Taken together, DNA damage and repair capacity can be a biomarker of aging. Reduced expression of DNA polymerase δ1 may be responsible for the decrease of DNA repair capacity in senescent cells.

  4. Both genetic and dietary factors underlie individual differences in DNA damage levels and DNA repair capacity.

    PubMed

    Slyskova, Jana; Lorenzo, Yolanda; Karlsen, Anette; Carlsen, Monica H; Novosadova, Vendula; Blomhoff, Rune; Vodicka, Pavel; Collins, Andrew R

    2014-04-01

    The interplay between dietary habits and individual genetic make-up is assumed to influence risk of cancer, via modulation of DNA integrity. Our aim was to characterize internal and external factors that underlie inter-individual variability in DNA damage and repair and to identify dietary habits beneficial for maintaining DNA integrity. Habitual diet was estimated in 340 healthy individuals using a food frequency questionnaire and biomarkers of antioxidant status were quantified in fasting blood samples. Markers of DNA integrity were represented by DNA strand breaks, oxidized purines, oxidized pyrimidines and a sum of all three as total DNA damage. DNA repair was characterized by genetic variants and functional activities of base and nucleotide excision repair pathways. Sex, fruit-based food consumption and XPG genotype were factors significantly associated with the level of DNA damage. DNA damage was higher in women (p=0.035). Fruit consumption was negatively associated with the number of all measured DNA lesions, and this effect was mediated mostly by β-cryptoxanthin and β-tocopherol (p<0.05). XPG 1104His homozygotes appeared more vulnerable to DNA damage accumulation (p=0.001). Sex and individual antioxidants were also associated with DNA repair capacity; both the base and nucleotide excision repairs were lower in women and the latter increased with higher plasma levels of ascorbic acid and α-carotene (p<0.05). We have determined genetic and dietary factors that modulate DNA integrity. We propose that the positive health effect of fruit intake is partially mediated via DNA damage suppression and a simultaneous increase in DNA repair capacity. PMID:24674629

  5. SDF-1 enhances wound healing of critical-sized calvarial defects beyond self-repair capacity.

    PubMed

    Jin, Qiming; Giannobile, William V

    2014-01-01

    Host blood circulating stem cells are an important cell source that participates in the repair of damaged tissues. The clinical challenge is how to improve the recruitment of circulating stem cells into the local wound area and enhance tissue regeneration. Stromal-derived factor-1 (SDF-1) has been shown to be a potent chemoattractant of blood circulating stem cells into the local wound microenvironment. In order to investigate effects of SDF-1 on bone development and the repair of a large bone defect beyond host self-repair capacity, the BMP-induced subcutaneous ectopic bone formation and calvarial critical-sized defect murine models were used in this preclinical study. A dose escalation of SDF-1 were loaded into collagen scaffolds containing BMP, VEGF, or PDGF, and implanted into subcutaneous sites at mouse dorsa or calvarial critical-sized bone defects for 2 and 4 weeks. The harvested biopsies were examined by microCT and histology. The results demonstrated that while SDF-1 had no effect in the ectopic bone model in promoting de novo osteogenesis, however, in the orthotopic bone model of the critical-sized defects, SDF-1 enhanced calvarial critical-sized bone defect healing similar to VEGF, and PDGF. These results suggest that SDF-1 plays a role in the repair of large critical-sized defect where more cells are needed while not impacting de novo bone formation, which may be associated with the functions of SDF-1 on circulating stem cell recruitment and angiogenesis.

  6. SDF-1 Enhances Wound Healing of Critical-Sized Calvarial Defects beyond Self-Repair Capacity

    PubMed Central

    Jin, Qiming; Giannobile, William V.

    2014-01-01

    Host blood circulating stem cells are an important cell source that participates in the repair of damaged tissues. The clinical challenge is how to improve the recruitment of circulating stem cells into the local wound area and enhance tissue regeneration. Stromal-derived factor-1 (SDF-1) has been shown to be a potent chemoattractant of blood circulating stem cells into the local wound microenvironment. In order to investigate effects of SDF-1 on bone development and the repair of a large bone defect beyond host self-repair capacity, the BMP-induced subcutaneous ectopic bone formation and calvarial critical-sized defect murine models were used in this preclinical study. A dose escalation of SDF-1 were loaded into collagen scaffolds containing BMP, VEGF, or PDGF, and implanted into subcutaneous sites at mouse dorsa or calvarial critical-sized bone defects for 2 and 4 weeks. The harvested biopsies were examined by microCT and histology. The results demonstrated that while SDF-1 had no effect in the ectopic bone model in promoting de novo osteogenesis, however, in the orthotopic bone model of the critical-sized defects, SDF-1 enhanced calvarial critical-sized bone defect healing similar to VEGF, and PDGF. These results suggest that SDF-1 plays a role in the repair of large critical-sized defect where more cells are needed while not impacting de novo bone formation, which may be associated with the functions of SDF-1 on circulating stem cell recruitment and angiogenesis. PMID:24800841

  7. Maintenance of xylem Network Transport Capacity: A Review of Embolism Repair in Vascular Plants

    PubMed Central

    Brodersen, Craig R.; McElrone, Andrew J.

    2013-01-01

    Maintenance of long distance water transport in xylem is essential to plant health and productivity. Both biotic and abiotic environmental conditions lead to embolism formation within the xylem resulting in lost transport capacity and ultimately death. Plants exhibit a variety of strategies to either prevent or restore hydraulic capacity through cavitation resistance with specialized anatomy, replacement of compromised conduits with new growth, and a metabolically active embolism repair mechanism. In recent years, mounting evidence suggests that metabolically active cells surrounding the xylem conduits in some, but not all, species are capable of restoring hydraulic conductivity. This review summarizes our current understanding of the osmotically driven embolism repair mechanism, the known genetic and anatomical components related to embolism repair, rehydration pathways through the xylem, and the role of capacitance. Anatomical differences between functional plant groups may be one of the limiting factors that allow some plants to refill while others do not, but further investigations are necessary to fully understand this dynamic process. Finally, xylem networks should no longer be considered an assemblage of dead, empty conduits, but instead a metabolically active tissue finely tuned to respond to ever changing environmental cues. PMID:23630539

  8. Melatonin enhances DNA repair capacity possibly by affecting genes involved in DNA damage responsive pathways

    PubMed Central

    2013-01-01

    Background Melatonin, a hormone-like substance involved in the regulation of the circadian rhythm, has been demonstrated to protect cells against oxidative DNA damage and to inhibit tumorigenesis. Results In the current study, we investigated the effect of melatonin on DNA strand breaks using the alkaline DNA comet assay in breast cancer (MCF-7) and colon cancer (HCT-15) cell lines. Our results demonstrated that cells pretreated with melatonin had significantly shorter Olive tail moments compared to non-melatonin treated cells upon mutagen (methyl methanesulfonate, MMS) exposure, indicating an increased DNA repair capacity after melatonin treatment. We further examined the genome-wide gene expression in melatonin pretreated MCF-7 cells upon carcinogen exposure and detected altered expression of many genes involved in multiple DNA damage responsive pathways. Genes exhibiting altered expression were further analyzed for functional interrelatedness using network- and pathway-based bioinformatics analysis. The top functional network was defined as having relevance for “DNA Replication, Recombination, and Repair, Gene Expression, [and] Cancer”. Conclusions These findings suggest that melatonin may enhance DNA repair capacity by affecting several key genes involved in DNA damage responsive pathways. PMID:23294620

  9. Estrogen Receptor Expression Is Associated with DNA Repair Capacity in Breast Cancer

    PubMed Central

    Matta, Jaime; Morales, Luisa; Ortiz, Carmen; Adams, Damian; Vargas, Wanda; Casbas, Patricia; Dutil, Julie; Echenique, Miguel; Suárez, Erick

    2016-01-01

    Estrogen-receptor-positive (ER+) tumors employ complex signaling that engages in crosstalk with multiple pathways through genomic and non-genomic regulation. A greater understanding of these pathways is important for developing improved biomarkers that can better determine treatment choices, risk of recurrence and cancer progression. Deficiencies in DNA repair capacity (DRC) is a hallmark of breast cancer (BC); therefore, in this work we tested whether ER signaling influences DRC. We analyzed the association between ER positivity (% receptor activation) and DRC in 270 BC patients, then further stratified our analysis by HER2 receptor status. Our results show that among HER2 negative, the likelihood of having low DRC values among ER- women is 1.92 (95% CI: 1.03, 3.57) times the likelihood of having low DRC values among ER+ women, even adjusting for different potential confounders (p<0.05); however, a contrary pattern was observed among HER2 positives women. In conclusion, there is an association between DRC levels and ER status, and this association is modified by HER2 receptor status. Adding a DNA repair capacity test to hormone receptor testing may provide new information on defective DNA repair phenotypes, which could better stratify BC patients who have ER+ tumors. ER+/HER2- tumors are heterogeneous, incompletely defined, and clinically challenging to treat; the addition of a DRC test could better characterize and classify these patients as well as help clinicians select optimal therapies, which could improve outcomes and reduce recurrences. PMID:27032101

  10. Mutagenesis by Cytostatic Alkylating Agents in Yeast Strains of Differing Repair Capacities

    PubMed Central

    Ruhland, Axel; Brendel, Martin

    1979-01-01

    Reversion of two nuclear ochre nonsense alleles and cell inactivation induced by mono-, bi-, and tri-functional alkylating agents and by UV has been investigated in stationary-phase haploid cells of yeast strains with differing capacities for DNA repair. The ability to survive alkylation damage is correlated with UV repair capacity, a UV-resistant and UV-mutable strain (RAD REV) being least and a UV-sensitive and UV-nonmutable strain (rad1 rev3) most sensitive. Mutagenicity of alkylating agents is highest in the former and is abolished in the latter strain. Deficiency in excision repair (rad1 rad2) or in the RAD18 function does not lead to enhanced mutability. Mutagenesis by the various agents is characterized by a common pattern of induction of locus-specific revertants and suppressor mutants. Induction kinetics are mostly linear, but UV-induced reversion in the RAD REV strain follows higher-than-linear (probably "quadratic") kinetics. The alkylating agent cyclophosphamide, usually considered inactive without metabolic conversion, reduces colony-forming ability and induces revertants in a manner similar but not identical to the other chemicals tested. These findings are taken to support the concept of mutagenesis by misrepair after alkylation, which albeit sharing common features with the mechanism of UV-induced reversion, can be distinguished therefrom. PMID:387518

  11. DNA damage and repair capacity in workers exposed to low concentrations of benzene.

    PubMed

    Lovreglio, Piero; Doria, Denise; Fracasso, Maria Enrica; Barbieri, Anna; Sabatini, Laura; Drago, Ignazio; Violante, Francesco S; Soleo, Leonardo

    2016-03-01

    DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling-station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t-muconic acid, S-phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m(3)), attendants (median 13.8 µg/m(3)), and controls (median 4.1 µg/m(3)). There were no differences in TI and 8-oxodG among the three groups, or between smokers and non-smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2 O2 -damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained. PMID:26646167

  12. DNA damage and repair capacity in workers exposed to low concentrations of benzene.

    PubMed

    Lovreglio, Piero; Doria, Denise; Fracasso, Maria Enrica; Barbieri, Anna; Sabatini, Laura; Drago, Ignazio; Violante, Francesco S; Soleo, Leonardo

    2016-03-01

    DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling-station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t-muconic acid, S-phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m(3)), attendants (median 13.8 µg/m(3)), and controls (median 4.1 µg/m(3)). There were no differences in TI and 8-oxodG among the three groups, or between smokers and non-smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2 O2 -damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained.

  13. Direct and indirect roles of RECQL4 in modulating base excision repair capacity.

    PubMed

    Schurman, Shepherd H; Hedayati, Mohammad; Wang, ZhengMing; Singh, Dharmendra K; Speina, Elzbieta; Zhang, Yongqing; Becker, Kevin; Macris, Margaret; Sung, Patrick; Wilson, David M; Croteau, Deborah L; Bohr, Vilhelm A

    2009-09-15

    RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund-Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werner's syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H(2)O(2)-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H(2)O(2)-induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H(2)O(2), RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase beta, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity.

  14. Enhanced capacity of DNA repair in human cytomegalovirus-infected cells

    SciTech Connect

    Nishiyama, Y.; Rapp, F.

    1981-04-01

    Plaque formation in Vero cells by UV-irradiated herpes simplex virus was enhanced by infection with human cytomegalovirus (HCMV), UV irradiation, or treatment with methylmethanesulfonate. Preinfection of Vero cells with HCMV enhanced reactivation of UV-irradiated herpes simplex virus more significantly than did treatment with UV or methylmethanesulfonate alone. A similar enhancement by HCMV was observed in human embryonic fibroblasts, but not in xeroderma pigmentosum (XP12BE) cells. It was also found that HCMV infection enhanced hydroxyurea-resistant DNA synthesis induced by UV light or methylmethanesulfonate. Alkaline sucrose gradient sedimentation analysis revealed an enhanced rate of synthesis of all size classes of DNA in UV-irradiated HCMV-infected Vero cells. However, HCMV infection did not induce repairable lesions in cellular DNA and did not significantly inhibit host cell DNA synthesis, unlike UV or methylmethanesulfonate. These results indicate that HCMV enhanced DNA repair capacity in the host cells without producing detectable lesions in cellular DNA and without inhibiting DNA synthesis. This repair appeared to be error proof for UV-damaged herpes simplex virus DNA when tested with herpes simplex virus thymidine kinase-negative mutants.

  15. Evaluation of radioinduced damage and repair capacity in blood lymphocytes of breast cancer patients.

    PubMed

    Nascimento, P A; da Silva, M A; Oliveira, E M; Suzuki, M F; Okazaki, K

    2001-02-01

    Genetic damage caused by ionizing radiation and repair capacity of blood lymphocytes from 3 breast cancer patients and 3 healthy donors were investigated using the comet assay. The comets were analyzed by two parameters: comet tail length and visual classification. Blood samples from the donors were irradiated in vitro with a 60Co source at a dose rate of 0.722 Gy/min, with a dose range of 0.2 to 4.0 Gy and analyzed immediately after the procedure and 3 and 24 h later. The basal level of damage and the radioinduced damage were higher in lymphocytes from breast cancer patients than in lymphocytes from healthy donors. The radioinduced damage showed that the two groups had a similar response when analyzed immediately after the irradiations. Therefore, while the healthy donors presented a considerable reduction of damage after 3 h, the patients had a higher residual damage even 24 h after exposure. The repair capacity of blood lymphocytes from the patients was slower than that of lymphocytes from healthy donors. The possible influence of age, disease stage and mutations in the BRCA1 and BRCA2 genes are discussed. Both parameters adopted proved to be sensitive and reproducible: the dose-response curves for DNA migration can be used not only for the analysis of cellular response but also for monitoring therapeutic interventions. Lymphocytes from the breast cancer patients presented an initial radiosensitivity similar to that of healthy subjects but a deficient repair mechanism made them more vulnerable to the genotoxic action of ionizing radiation. However, since lymphocytes from only 3 patients and 3 normal subjects were analyzed in the present paper, additional donors will be necessary for a more accurate evaluation. PMID:11175491

  16. Kidney-derived mesenchymal stem cells contribute to vasculogenesis, angiogenesis and endothelial repair

    PubMed Central

    Chen, Jun; Park, Hyeong-Cheon; Addabbo, Francesco; Ni, Jie; Pelger, Edward; Li, Houwei; Plotkin, Matthew; Goligorsky, Michael S.

    2009-01-01

    We isolated a clonal cell line (4E) from kidneys of mice expressing green fluorescent protein controlled by the endothelial-specific Tie2 promoter. When grown in a three-dimensional matrigel matrix they formed a fluorescent capillary network. In vivo angiogenesis assays using growth factor-depleted matrigel implanted plugs promoted a moderate angiogenesis of host endothelial cells. Using vascular endothelial growth factor (VEGF)-A and fibroblast growth factor-2 in the plugs containing 4E-cells resulted in a robust vasculogenesis. Transplantation of 4E cells into mice with acute renal ischemia showed selective engraftment in the ischemic kidney which promoted tubular regeneration by increasing epithelial proliferation and inhibiting apoptosis. This resulted in an accelerated functional recovery 3 days after ischemia. These mice showed a 5-fold increase in tissue VEGF expression compared to controls, but no difference in plasma VEGF level corresponding with better preservation of peritubular capillaries, perhaps due to a local paracrine effect following systemic 4E infusion. One month after ischemia, 9% of engrafted 4E cells expressed green fluorescent protein in the peritubular region while half of them expressed α-smooth muscle actin. Our study shows that kidney mesenchymal stem cells are capable of differentiation toward endothelial and smooth muscle cell lineages in vitro and in vivo, support new blood vessel formation in favorable conditions and promote functional recovery of an ischemic kidney. PMID:18596729

  17. A pilot study of the effect of spironolactone therapy on exercise capacity and endothelial dysfunction in pulmonary arterial hypertension: study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Pulmonary arterial hypertension is a rare disorder associated with poor survival. Endothelial dysfunction plays a central role in the pathogenesis and progression of pulmonary arterial hypertension. Inflammation appears to drive this dysfunctional endothelial phenotype, propagating cycles of injury and repair in genetically susceptible patients with idiopathic and disease-associated pulmonary arterial hypertension. Therapy targeting pulmonary vascular inflammation to interrupt cycles of injury and repair and thereby delay or prevent right ventricular failure and death has not been tested. Spironolactone, a mineralocorticoid and androgen receptor antagonist, has been shown to improve endothelial function and reduce inflammation. Current management of patients with pulmonary arterial hypertension and symptoms of right heart failure includes use of mineralocorticoid receptor antagonists for their diuretic and natriuretic effects. We hypothesize that initiating spironolactone therapy at an earlier stage of disease in patients with pulmonary arterial hypertension could provide additional benefits through anti-inflammatory effects and improvements in pulmonary vascular function. Methods/Design Seventy patients with pulmonary arterial hypertension without clinical evidence of right ventricular failure will be enrolled in a randomized, double-blinded, placebo-controlled trial to investigate the effect of early treatment with spironolactone on exercise capacity, clinical worsening and vascular inflammation in vivo. Our primary endpoint is change in placebo-corrected 6-minute walk distance at 24 weeks and the incidence of clinical worsening in the spironolactone group compared to placebo. At a two-sided alpha level of 0.05, we will have at least 84% power to detect an effect size (group mean difference divided by standard deviation) of 0.9 for the difference in the change of 6-minute walk distance from baseline between the two groups. Secondary endpoints include

  18. A modified host-cell reactivation assay to quantify DNA repair capacity in cryopreserved peripheral lymphocytes.

    PubMed

    Mendez, Pedro; Taron, Miquel; Moran, Teresa; Fernandez, Marco A; Requena, Gerard; Rosell, Rafael

    2011-06-10

    The host-cell reactivation assay (HCRA) is a functional assay that allows the identification of the genes responsible for DNA repair-deficient syndromes, such as Xeroderma pigmentosum, by cross-complementation experiments. It has also been used in molecular epidemiology studies to correlate the low nucleotide excision repair pathway function in peripheral blood lymphocytes with an increased risk of bladder, head and neck, skin and lung cancers. Herein, we present the technical validation of a newly modified HCRA, where nucleofection is used for the transfection of the pmaxGFP plasmid into cryopreserved peripheral blood lymphocytes (PBLs) or lymphoblastoid cell lines. In each sample, 20-24h after transfection, the relative DNA repair capacity (DRC) was quantified by flow cytometry, comparing the transfection efficiency of nucleoporated cells with undamaged plasmid to those transfected with UV-light damaged plasmid in the seven cell lines that were characterized by different DNA repair phenotypes. Dead cells were excluded from the analysis. We observed a high reproducibility of the relative DRC, transfection efficiency and cell viability. The inter-experimental normalization of the flow cytometry resulted in an increased data accuracy and reproducibility. The amount of cells required for each transfection reaction was reduced fourfold, without affecting the final relative DRC. Furthermore, our HCRA demonstrated strong discrimination power in the UV-light dose-response, both in lymphoblastoid cell lines and cryopreserved PBLs. We also observed a strong correlation of the relative DRC data, when samples were measured against two independent batches of both damaged and undamaged plasmid DNA. The relative DRC variable shows a normal distribution when analyzed in the cryopreserved PBLs from a cohort of 35 lung cancer patients and a 5.59-fold variation in the relative DRC is identified among our patients. The mitotic dynamic was discarded as a confounding factor for the

  19. Bevacizumab radiosensitizes non-small cell lung cancer xenografts by inhibiting DNA double-strand break repair in endothelial cells.

    PubMed

    Gao, Hui; Xue, Jianxin; Zhou, Lin; Lan, Jie; He, Jiazhuo; Na, Feifei; Yang, Lifei; Deng, Lei; Lu, You

    2015-08-28

    The aims of this study were to evaluate the effects of biweekly bevacizumab administration on a tumor microenvironment and to investigate the mechanisms of radiosensitization that were induced by it. Briefly, bevacizumab was administered intravenously to Balb/c nude mice bearing non-small cell lung cancer (NSCLC) H1975 xenografts; in addition, bevacizumab was added to NSCLC or endothelial cells (ECs) in vitro, followed by irradiation (IR). The anti-tumor efficacy, anti-angiogenic efficacy and repair of DNA double-strand breaks (DSBs) were evaluated. The activation of signaling pathways was determined using immunoprecipitation (IP) and WB analyses. Finally, biweekly bevacizumab administration inhibited the growth of H1975 xenografts and induced vascular normalization periodically. Bevacizumab more significantly increased cellular DSB and EC apoptosis when administered 1 h prior to 12 Gy/1f IR than when administered 5 days prior to IR, thereby inhibiting tumor angiogenesis and growth. In vitro, bevacizumab more effectively increased DSBs and apoptosis prior to IR and inhibited the clonogenic survival of ECs but not NSCLC cells. Using IP and WB analyses, we confirmed that bevacizumab can directly inhibit the phosphorylation of components of the VEGR2/PI3K/Akt/DNA-PKcs signaling pathway that are induced by IR in ECs. In conclusion, bevacizumab radiosensitizes NSCLC xenografts mainly by inhibiting DSB repair in ECs rather than by inducing vascular normalization.

  20. DEVELOPMENT OF A RATIO OF EMERGENT TO TOTAL HERNIA REPAIRS AS A SURGICAL CAPACITY METRIC

    PubMed Central

    Samuel, Jonathan C; Tyson, Anna F; Mabedi, Charles; Mulima, Gift; Cairns, Bruce A; Varela, Carlos; Charles, Anthony G

    2014-01-01

    Summary INTRODUCTION Non-communicable diseases including surgical conditions are gaining attention in developing countries. Despite this there are few metrics for surgical capacity. We hypothesized that (a) the ratio of emergent to total hernia repairs (E/TH) would correlate with per capita health care expenditures for any given country, and (b) the E/TH is easy to obtain in resource-poor settings. METHODS We performed a systematic review to identify the E/TH for as many countries as possible (Prospero registry CRD42013004645). We screened 1285 English language publications since 1990; 23 met inclusion criteria. Primary data was also collected from Kamuzu Central Hospital (KCH) in Lilongwe, Malawi. A total of 13 countries were represented. Regression analysis was used to determine the correlation between per capita healthcare spending and the E/TH. RESULTS There is a strong correlation between the log values of the ratio emergent to total groin hernias and the per capita health care spending that is robust across country income levels (R2=0·823). Primary data from KCH was easily obtained and demonstrated a similar correlation. CONCLUSIONS The ratio of emergent to total groin hernias is a potential measure of surgical capacity using data that is easily attainable. Further studies should validate this metric against other accepted health care capacity indicators. PMID:25084098

  1. Oxidative damage to RPA limits the nucleotide excision repair capacity of human cells

    PubMed Central

    Guven, Melisa; Brem, Reto; Macpherson, Peter; Peacock, Matthew; Karran, Peter

    2015-01-01

    Nucleotide excision repair (NER) protects against sunlight-induced skin cancer. Defective NER is associated with photosensitivity and a high skin cancer incidence. Some clinical treatments that cause photosensitivity can also increase skin cancer risk. Among these, the immunosuppressant azathioprine and the fluoroquinolone antibiotics ciprofloxacin and ofloxacin, interact with UVA radiation to generate reactive oxygen species (ROS) that diminish NER capacity by causing protein damage. The RPA DNA binding protein plays a pivotal role in DNA metabolism and is an essential component of NER. The relationship between protein oxidation and NER inhibition was investigated in cultured human cells expressing different levels of RPA. We show here that RPA is limiting for NER and that oxidative damage to RPA compromises NER capability. Our findings reveal that cellular RPA is surprisingly vulnerable to oxidation and we identify oxidized forms of RPA that are associated with impaired NER. The vulnerability of NER to inhibition by oxidation provides a connection between cutaneous photosensitivity, protein damage and increased skin cancer risk. Our findings emphasize that damage to DNA repair proteins, as well as to DNA itself is likely to be an important contributor to skin cancer risk. PMID:26134950

  2. A reversal of age-dependent proliferative capacity of endothelial progenitor cells from different species origin in in vitro condition

    PubMed Central

    Hassanpour, Mehdi; Cheraghi, Omid; Siavashi, Vahid; Rahbarghazi, Reza; Nouri, Mohammad

    2016-01-01

    Introduction: A large number of cardiovascular disorders and abnormalities, notably accelerated vascular deficiencies could be related to aging changes and increased length of life. During the past decades, the discovery of different stem cells facilitates ongoing attempts for attenuating many disorders, especially in vascular beds. Endothelial progenitor cells (EPCs) are a subtype of stem cells that have potent capacity to differentiate into mature endothelial cells (ECs). However, some documented studies reported an age-related decline in proliferation and function of many stem cells. There is no data on aging effect upon proliferation and morphological feature of EPCs. Methods: To show aging effect on EPCs proliferation and multipotentiality, bone marrow samples were provided from old and young cases in three different species; human, mouse and dog. After 7 days of culture, the cell morphology and clonogenic capacity were evaluated. We also calculated the mean number of colonies both in bone marrow samples from old and young subjects. To confirm the cell phenotype, isolated cells were immune-phenotyped by a panel of antibodies against Tie-2, CD133 and CD309 markers. Results: Our results showed that EPCs exhibited prominent spindle form in all bone marrow samples from young cases while the cell shape became more round by aging. Notably, the number of colonies was reduced in aged samples as compared to parallel young subject samples (P < 0.05). We also detected that the expression of endothelial related markers diminished by aging. Conclusion: The results of this study suggest that the age-related vascular abnormalities could be presumably related to the decline in stemness capacity of EPCs. PMID:27777694

  3. Vascular Endothelial Growth Factor-Delivery Systems for Cardiac Repair: An Overview

    PubMed Central

    Simón-Yarza, Teresa; Formiga, Fabio R.; Tamayo, Esther; Pelacho, Beatriz; Prosper, Felipe; Blanco-Prieto, María J.

    2012-01-01

    Since the discovery of the Vascular Endothelial Growth Factor (VEGF) and its leading role in the angiogenic process, this has been seen as a promising molecule for promoting neovascularization in the infarcted heart. However, even though several clinical trials were initiated, no therapeutic effects were observed, due in part to the short half life of this factor when administered directly to the tissue. In this context, drug delivery systems appear to offer a promising strategy to overcome limitations in clinical trials of VEGF. The aim of this paper is to review the principal drug delivery systems that have been developed to administer VEGF in cardiovascular disease. Studies published in the last 5 years are reviewed and the main features of these systems are explained. The tissue engineering concept is introduced as a therapeutic alternative that holds promise for the near future. PMID:22737191

  4. Existence, Functional Impairment, and Lung Repair Potential of Endothelial Colony-Forming Cells in Oxygen-Induced Arrested Alveolar Growth

    PubMed Central

    Alphonse, Rajesh S.; Vadivel, Arul; Fung, Moses; Shelley, William Chris; Critser, Paul John; Ionescu, Lavinia; O’Reilly, Megan; Ohls, Robin K.; McConaghy, Suzanne; Eaton, Farah; Zhong, Shumei; Yoder, Merv; Thébaud, Bernard

    2014-01-01

    Background Bronchopulmonary dysplasia and emphysema are life-threatening diseases resulting from impaired alveolar development or alveolar destruction. Both conditions lack effective therapies. Angiogenic growth factors promote alveolar growth and contribute to alveolar maintenance. Endothelial colony-forming cells (ECFCs) represent a subset of circulating and resident endothelial cells capable of self-renewal and de novo vessel formation. We hypothesized that resident ECFCs exist in the developing lung, that they are impaired during arrested alveolar growth in experimental bronchopulmonary dysplasia, and that exogenous ECFCs restore disrupted alveolar growth. Methods and Results Human fetal and neonatal rat lungs contain ECFCs with robust proliferative potential, secondary colony formation on replating, and de novo blood vessel formation in vivo when transplanted into immunodeficient mice. In contrast, human fetal lung ECFCs exposed to hyperoxia in vitro and neonatal rat ECFCs isolated from hyperoxic alveolar growth–arrested rat lungs mimicking bronchopulmonary dysplasia proliferated less, showed decreased clonogenic capacity, and formed fewer capillary-like networks. Intrajugular administration of human cord blood–derived ECFCs after established arrested alveolar growth restored lung function, alveolar and lung vascular growth, and attenuated pulmonary hypertension. Lung ECFC colony- and capillary-like network-forming capabilities were also restored. Low ECFC engraftment and the protective effect of cell-free ECFC-derived conditioned media suggest a paracrine effect. Long-term (10 months) assessment of ECFC therapy showed no adverse effects with persistent improvement in lung structure, exercise capacity, and pulmonary hypertension. Conclusions Impaired ECFC function may contribute to arrested alveolar growth. Cord blood–derived ECFC therapy may offer new therapeutic options for lung diseases characterized by alveolar damage. PMID:24710033

  5. Novel hyperbranched polyamidoamine nanoparticles for transfecting skeletal myoblasts with vascular endothelial growth factor gene for cardiac repair.

    PubMed

    Zhu, Kai; Guo, Changfa; Lai, Hao; Yang, Wuli; Xia, Yu; Zhao, Dong; Wang, Chunsheng

    2011-11-01

    We investigated the feasibility and efficacy of hyperbranched polyamidoamine (hPAMAM) mediated human vascular endothelial growth factor-165 (hVEGF(165)) gene transfer into skeletal myoblasts for cardiac repair. The hPAMAM was synthesized using a modified one-pot method. Encapsulated DNA was protected by hPAMAM from degradation for over 120 min. The transfection efficiency of hPAMAM in myoblasts was 82.6 ± 7.0% with cell viability of 94.6 ± 1.4% under optimal conditions. The hPAMAM showed much higher transfection efficiency (P < 0.05) than polyetherimide and Lipofectamine 2000 with low cytotoxicity. The transfected skeletal myoblasts gave stable hVEGF(165) expression for 18 days. After transplantation of hPAMAM-hVEGF(165) transfected cells, apoptotic myocardial cells decreased at day 1 and heart function improved at day 28, with increased neovascularization (P < 0.05). These results indicate that hPAMAM-based gene delivery into myoblasts is feasible and effective and may serve as a novel and promising non-viral DNA vehicle for gene therapy in myocardial infarction.

  6. Central Role of eNOS in the Maintenance of Endothelial Homeostasis

    PubMed Central

    Rodriguez-Mateos, Ana; Kelm, Malte

    2015-01-01

    Abstract Significance: Disruption of endothelial function is considered a key event in the development and progression of atherosclerosis. Endothelial nitric oxide synthase (eNOS) is a central regulator of cellular function that is important to maintain endothelial homeostasis. Recent Advances: Endothelial homeostasis encompasses acute responses such as adaption of flow to tissue's demand and more sustained responses to injury such as re-endothelialization and sprouting of endothelial cells (ECs) and attraction of circulating angiogenic cells (CAC), both of which support repair of damaged endothelium. The balance and the intensity of endothelial damage and repair might be reflected by changes in circulating endothelial microparticles (EMP) and CAC. Flow-mediated vasodilation (FMD) is a generally accepted clinical read-out of NO-dependent vasodilation, whereas EMP are upcoming prognostically validated markers of endothelial injury and CAC are reflective of the regenerative capacity with both expressing a functional eNOS. These markers can be integrated in a clinical endothelial phenotype, reflecting the net result between damage from risk factors and endogenous repair capacity with NO representing a central signaling molecule. Critical Issues: Improvements of reproducibility and observer independence of FMD measurements and definitions of relevant EMP and CAC subpopulations warrant further research. Future Directions: Endothelial homeostasis may be a clinical therapeutic target for cardiovascular health maintenance. Antioxid. Redox Signal. 22, 1230–1242. PMID:25330054

  7. Ionizing radiation-induced mutation of human cells with different DNA repair capacities

    SciTech Connect

    Amundson, S.A.; Chen, D.J.

    1994-12-31

    We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational repair may contribute to both cell survival and mutation-induction following exposure to ionizing radiation. Such a mechanism may aid cell survival, but could also result in increased deleterious effects such as the unmasking of recessive mutations in cancer suppresser genes.

  8. Ionizing radiation-induced mutation of human cells with different DNA repair capacities

    NASA Astrophysics Data System (ADS)

    Amundson, S. A.; Chen, D. J.

    We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by alpha-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and alpha-particles. WTK1 is also more mutable by alpha-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while alpha-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-inducedtk - mutants of TK6, were not induced significantly by alpha-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational repair may contribute to both cell survival and mutation-induction following exposure to ionizing radiation. Such a mechanism may aid cell survival, but could also result in increased deleterious effects such as the unmasking of recessive mutations in cancer suppresser genes.

  9. White matter involvement after TBI: Clues to axon and myelin repair capacity.

    PubMed

    Armstrong, Regina C; Mierzwa, Amanda J; Marion, Christina M; Sullivan, Genevieve M

    2016-01-01

    Impact-acceleration forces to the head cause traumatic brain injury (TBI) with damage in white matter tracts comprised of long axons traversing the brain. White matter injury after TBI involves both traumatic axonal injury (TAI) and myelin pathology that evolves throughout the post-injury time course. The axon response to initial mechanical forces and secondary insults follows the process of Wallerian degeneration, which initiates as a potentially reversible phase of intra-axonal damage and proceeds to an irreversible phase of axon fragmentation. Distal to sites of axon disconnection, myelin sheaths remain for prolonged periods, which may activate neuroinflammation and inhibit axon regeneration. In addition to TAI, TBI can cause demyelination of intact axons. These evolving features of axon and myelin pathology also represent opportunities for repair. In experimental TBI, demyelinated axons exhibit remyelination, which can serve to both protect axons and facilitate recovery of function. Myelin remodeling may also contribute to neuroplasticity. Efficient clearance of myelin debris is a potential target to attenuate the progression of chronic pathology. During the early phase of Wallerian degeneration, interventions that prevent the transition from reversible damage to axon disconnection warrant the highest priority, based on the poor regenerative capacity of axons in the CNS. Clinical evaluation of TBI will need to address the challenge of accurately detecting the extent and stage of axon damage. Distinguishing the complex white matter changes associated with axons and myelin is necessary for interpreting advanced neuroimaging approaches and for identifying a broader range of therapeutic opportunities to improve outcome after TBI.

  10. Aerobic exercise capacity remains normal despite impaired endothelial function in the micro- and macrocirculation of physically active IDDM patients.

    PubMed

    Veves, A; Saouaf, R; Donaghue, V M; Mullooly, C A; Kistler, J A; Giurini, J M; Horton, E S; Fielding, R A

    1997-11-01

    The aim of the present study was to examine if diabetes in the absence of neuropathy affects the exercising capacity of IDDM patients, and whether regular, intense training has a beneficial effect on endothelial function. Five groups of subjects were studied: 23 healthy control subjects who exercised regularly (age 33 +/- 6 years), 23 nonneuropathic type 1 diabetic patients who exercised regularly (age 33 +/- 6 years, IDDM duration 11 +/- 8 years), 7 neuropathic type 1 diabetic patients who exercised regularly (age 36 +/- 7 years, IDDM duration 22 +/- 8 years), 18 healthy subjects who did not exercise regularly (age 34 +/- 7 years), and 5 nonneuropathic type 1 diabetic patients who did not exercise regularly (age 31 +/- 4 years, IDDM duration 20 +/- 3 years). All groups were matched for age, sex, and body weight. No differences existed in the energy expenditure per week in physical activity among the three exercising groups or between the two nonexercising groups. The maximal oxygen uptake was similar between control and diabetic nonneuropathic exercisers, and among diabetic neuropathic exercisers, control nonexercisers, and diabetic nonexercisers; however, a significant difference existed between the first two and the last three groups (P < 0.0001). A stepwise increase was found in the resting heart rate among the groups, ranging from the lowest in control exercisers to the highest in diabetic nonexercisers, but the maximal heart rate was lower only in diabetic neuropathic exercisers compared with all other groups (P < 0.05). Assessments of endothelial function in both macro- and microcirculation were performed in 12 control exercisers, 10 diabetic nonneuropathic exercisers, 5 diabetic neuropathic exercisers, 17 control nonexercisers, and 4 diabetic nonexercisers. When all diabetic patients were considered as one group and all control subjects as another, the microcirculation endothelial function in the diabetic group was reduced compared with the control subjects

  11. Aging-Induced Dysregulation of Dicer1-Dependent MicroRNA Expression Impairs Angiogenic Capacity of Rat Cerebromicrovascular Endothelial Cells

    PubMed Central

    2013-01-01

    Age-related impairment of angiogenesis is likely to play a central role in cerebromicrovascular rarefaction and development of vascular cognitive impairment, but the underlying mechanisms remain elusive. To test the hypothesis that dysregulation of Dicer1 (ribonuclease III, a key enzyme of the microRNA [miRNA] machinery) impairs endothelial angiogenic capacity in aging, primary cerebromicrovascular endothelial cells (CMVECs) were isolated from young (3 months old) and aged (24 months old) Fischer 344 × Brown Norway rats. We found an age-related downregulation of Dicer1 expression both in CMVECs and in small cerebral vessels isolated from aged rats. In aged CMVECs, Dicer1 expression was increased by treatment with polyethylene glycol–catalase. Compared with young cells, aged CMVECs exhibited altered miRNA expression profile, which was associated with impaired proliferation, adhesion to vitronectin, collagen and fibronectin, cellular migration (measured by a wound-healing assay using electric cell–substrate impedance sensing technology), and impaired ability to form capillary-like structures. Overexpression of Dicer1 in aged CMVECs partially restored miRNA expression profile and significantly improved angiogenic processes. In young CMVECs, downregulation of Dicer1 (siRNA) resulted in altered miRNA expression profile associated with impaired proliferation, adhesion, migration, and tube formation, mimicking the aging phenotype. Collectively, we found that Dicer1 is essential for normal endothelial angiogenic processes, suggesting that age-related dysregulation of Dicer1-dependent miRNA expression may be a potential mechanism underlying impaired angiogenesis and cerebromicrovascular rarefaction in aging. PMID:23239824

  12. Aerobic endurance capacity affects spatial memory and SIRT1 is a potent modulator of 8-oxoguanine repair

    PubMed Central

    Sarga, Linda; Hart, Nikolett; Koch, Lauren; Britton, Steve; Hajas, Gyorgy; Boldogh, Istvan; Ba, Xuequing; Radak, Zsolt

    2013-01-01

    Regular exercise promotes brain function via a wide range of adaptive responses, including the increased expression of antioxidant and oxidative DNA damage-repairing systems. Accumulation of oxidized DNA base lesions and strand breaks is etiologically linked to for example aging processes and age-associated diseases. Here we tested whether exercise training has an impact on brain function, extent of neurogenesis, and expression of 8-oxoguanine DNA glycosylase-1 (Ogg1) and SIRT1 (silent mating type information regulation 2 homolog). To do so, we utilized strains of rats with low- and high- running capacity (LCR and HCR) and examined learning and memory, DNA synthesis, expression, and posttranslational modification of Ogg1 hippocampal cells. Our results showed that rats with higher aerobic/running capacity had better spatial memory, and expressed less Ogg1, when compared to LCR rats. Furthermore, exercise increased SIRT1 expression and decreased acetylated Ogg1 (AcOgg1) levels, a post-translational modification important for efficient repair of 8-oxoG. Our data on cell cultures revealed that nicotinamide, a SIRT1-specific inhibitor, caused the greatest increase in the acetylation of Ogg1, a finding further supported by our other observations that silencing SIRT1 also markedly increased the levels of AcOgg1. These findings imply that high-running capacity is associated with increased hippocampal function, and SIRT1 level/activity and inversely correlates with AcOgg1 levels and thereby the repair of genomic 8-oxoG. PMID:23973402

  13. Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines.

    PubMed

    Parfitt, S L; Milner, R J; Salute, M E; Hintenlang, D E; Farese, J P; Bacon, N J; Bova, F J; Rajon, D A; Lurie, D M

    2011-09-01

    Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC.

  14. Breast Cancer and DNA Repair Capacity: Association With Use of Multivitamin and Calcium Supplements

    PubMed Central

    Vergne, Yeidyly; Matta, Jaime; Morales, Luisa; Vargas, Wanda; Alvarez-Garriga, Carolina; Bayona, Manuel

    2013-01-01

    Context Breast cancer (BC) is the most common cancer in women, with over 1 million new cases diagnosed every year worldwide. Over recent decades, considerable interest has emerged regarding whether vitamins and/or other supplements can lower the risk of BC. However, previous epidemiologic studies that investigated the association between intake of multivitamin and supplements of single vitamins and minerals and BC risk have reported conflicting results. Whether vitamins can actually reduce BC risk is still controversial. Objective This study examined whether multivitamin and calcium use was associated with BC incidence and DNA repair capacity (DRC). Design The research team designed an observational, case-control study. Setting All work was performed at the Ponce School of Medicine and Health Sciences under the direct supervision of principal investigator Dr Jaime Matta. Participants Participants were 836 women recruited primarily from the private practices of oncologists, gynecologists, and surgeons in Puerto Rico. Intervention(s) A total of 312 individuals in the breast cancer (BC) group and 524 individuals in the control group were compared for their multivitamin and calcium intake, DRC levels, and other covariates. Outcome Measure(s) Odds ratios (OR), adjusted using both crude analysis and multiple logistic regression, were used as measures of association between BC and DRC and other selected variables. Results The BC group had 30% reduced odds of taking multivitamins and calcium as compared to controls: (1) OR = 0.7 (95% CI, 0.4–1.0; P = .073) for multivitamins and (2) OR = 0.7 (95% CI, 0.4–1.2; P = .167) for calcium. Women with low DRC had 50% lower odds of taking calcium and 30% lower odds of currently taking vitamins OR = 0.5 (95% CI, 0.4–0.7; P = .001) for calcium and (2) OR = 0.7 (95% CI, 0.5–0.9.1; P = .047) for vitamins. Conclusions Although this study is a case-control study in which the risk of BC could not be assessed, results suggest that

  15. Gender differences in circulating endothelial progenitor cell colony-forming capacity and migratory activity in middle-aged adults.

    PubMed

    Hoetzer, Greta L; MacEneaney, Owen J; Irmiger, Heather M; Keith, Rebecca; Van Guilder, Gary P; Stauffer, Brian L; DeSouza, Christopher A

    2007-01-01

    Middle-aged women have a lower prevalence and incidence of cardiovascular events compared with men. The mechanisms responsible for this gender-specific difference are unclear. Numeric and functional impairments of bone marrow-derived circulating endothelial progenitor cells (EPCs) are associated with increased cardiovascular and cerebrovascular morbidity and mortality. It is currently unknown whether there are gender-related differences in EPC number and function in middle-aged adults. We tested the hypothesis that EPCs isolated from middle-aged women demonstrate greater colony-forming capacity and migratory activity compared with men of similar age. Peripheral blood samples were collected from 50 sedentary adults, 25 men (59 +/- 1 years of age) and 25 women (58 +/- 1 years of age). Mononuclear cells were isolated and preplated for 2 days, and nonadherent cells were further cultured for 7 days to determine EPC colony-forming units. Migratory activity of EPCs was determined using a modified Boyden chamber. The number of EPC colony-forming units was significantly higher (approximately 150%) in samples collected from women (16 +/- 3) compared with that collected from men (7 +/- 1). In addition, EPC migration (relative fluorescent units) was approximately 40% greater in women (729 +/- 74) than in men (530 +/- 67). In conclusion, these results demonstrate that EPC colony-forming capacity and migratory activity are higher in middle-aged women than in men.

  16. Estimation of the effects of smoking and DNA repair capacity on coefficients of a carcinogenesis model for lung cancer

    PubMed Central

    Deng, Li; Kimmel, Marek; Foy, Millennia; Spitz, Margaret; Wei, Qingyi; Gorlova, Olga

    2009-01-01

    Numerous prospective and retrospective studies have clearly demonstrated a dose-related increased lung cancer risk associated with cigarette smoking, with evidence also for a genetic component to risk. In this study, using the two-stage clonal expansion stochastic model framework, for the first time we investigated the roles of both genetic susceptibility and smoking history in the initiation, clonal expansion, and malignant transformation processes in lung carcinogenesis, integrating information collected by a case–control study and a large-scale prospective cohort study. Our results show that individuals with suboptimal DNA repair capacity have enhanced transition rates of key events in carcinogenesis. PMID:19123470

  17. Exploration of methods to identify polymorphisms associated with variation in DNA repair capacity phenotypes.

    PubMed

    Jones, Irene M; Thomas, Cynthia B; Xi, Tina; Mohrenweiser, Harvey W; Nelson, David O

    2007-03-01

    Elucidating the relationship between polymorphic sequences and risk of common disease is a challenge. For example, although it is clear that variation in DNA repair genes is associated with familial cancer, aging and neurological disease, progress toward identifying polymorphisms associated with elevated risk of sporadic disease has been slow. This is partly due to the complexity of the genetic variation, the existence of large numbers of mostly low frequency variants and the contribution of many genes to variation in susceptibility. There has been limited development of methods to find associations between genotypes having many polymorphisms and pathway function or health outcome. We have explored several statistical methods for identifying polymorphisms associated with variation in DNA repair phenotypes. The model system used was 80 cell lines that had been resequenced to identify variation; 191 single nucleotide substitution polymorphisms (SNPs) are included, of which 172 are in 31 base excision repair pathway genes, 19 in 5 anti-oxidation genes, and DNA repair phenotypes based on single strand breaks measured by the alkaline Comet assay. Univariate analyses were of limited value in identifying SNPs associated with phenotype variation. Of the multivariable model selection methods tested: the easiest that provided reduced error of prediction of phenotype was simple counting of the variant alleles predicted to encode proteins with reduced activity, which led to a genotype including 52 SNPs; the best and most parsimonious model was achieved using a two-step analysis without regard to potential functional relevance: first SNPs were ranked by importance determined by random forests regression (RFR), followed by cross-validation in a second round of RFR modeling that included ever more SNPs in declining order of importance. With this approach six SNPs were found to minimize prediction error. The results should encourage research into utilization of multivariate

  18. Exploration of methods to identify polymorphisms associated with variation in DNA repair capacity phenotypes

    SciTech Connect

    Jones, I M; Thomas, C B; Xi, T; Mohrenweiser, H W; Nelson, D O

    2006-07-03

    Elucidating the relationship between polymorphic sequences and risk of common disease is a challenge. For example, although it is clear that variation in DNA repair genes is associated with familial cancer, aging and neurological disease, progress toward identifying polymorphisms associated with elevated risk of sporadic disease has been slow. This is partly due to the complexity of the genetic variation, the existence of large numbers of mostly low frequency variants and the contribution of many genes to variation in susceptibility. There has been limited development of methods to find associations between genotypes having many polymorphisms and pathway function or health outcome. We have explored several statistical methods for identifying polymorphisms associated with variation in DNA repair phenotypes. The model system used was 80 cell lines that had been resequenced to identify variation; 191 single nucleotide substitution polymorphisms (SNPs) are included, of which 172 are in 31 base excision repair pathway genes, 19 in 5 anti-oxidation genes, and DNA repair phenotypes based on single strand breaks measured by the alkaline Comet assay. Univariate analyses were of limited value in identifying SNPs associated with phenotype variation. Of the multivariable model selection methods tested: the easiest that provided reduced error of prediction of phenotype was simple counting of the variant alleles predicted to encode proteins with reduced activity, which led to a genotype including 52 SNPs; the best and most parsimonious model was achieved using a two-step analysis without regard to potential functional relevance: first SNPs were ranked by importance determined by Random Forests Regression (RFR), followed by cross-validation in a second round of RFR modeling that included ever more SNPs in declining order of importance. With this approach 6 SNPs were found to minimize prediction error. The results should encourage research into utilization of multivariate

  19. The Use of Fiber-Reinforced Scaffolds Cocultured with Schwann Cells and Vascular Endothelial Cells to Repair Rabbit Sciatic Nerve Defect with Vascularization

    PubMed Central

    Gao, Hongyang; You, Yang; Zhang, Guoping; Zhao, Feng; Sha, Ziyi; Shen, Yong

    2013-01-01

    To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function. PMID:24490158

  20. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head.

    PubMed

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head.

  1. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head

    PubMed Central

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head. PMID:26629044

  2. Modulation of DNA-induced damage and repair capacity in humans after dietary intervention with lutein-enriched fermented milk.

    PubMed

    Herrero-Barbudo, Carmen; Soldevilla, Beatriz; Pérez-Sacristán, Belén; Blanco-Navarro, Inmaculada; Herrera, Mercedes; Granado-Lorencio, Fernando; Domínguez, Gemma

    2013-01-01

    Dietary factors provide protection against several forms of DNA damage. Additionally, consumer demand for natural products favours the development of bioactive food ingredients with health benefits. Lutein is a promising biologically active component in the food industry. The EFSA Panel on Dietetic Products, Nutrition and Allergies considers that protection from oxidative damage may be a beneficial physiological effect but that a cause and effect relationship has not been established. Thus, our aim was to evaluate the safety and potential functional effect of a lutein-enriched milk product using the Comet Assay in order to analyze the baseline, the induced DNA-damage and the repair capacity in the lymphocytes of 10 healthy donors before and after the intake of the mentioned product. Our data suggest that the regular consumption of lutein-enriched fermented milk results in a significant increase in serum lutein levels and this change is associated with an improvement in the resistance of DNA to damage and the capacity of DNA repair in lymphocytes. Our results also support the lack of a genotoxic effect at the doses supplied as well as the absence of interactions and side effects on other nutritional and biochemicals markers. PMID:24040187

  3. Erythropoietin and a nonerythropoietic peptide analog promote aortic endothelial cell repair under hypoxic conditions: role of nitric oxide

    PubMed Central

    Heikal, Lamia; Ghezzi, Pietro; Mengozzi, Manuela; Stelmaszczuk, Blanka; Feelisch, Martin; Ferns, Gordon AA

    2016-01-01

    The cytoprotective effects of erythropoietin (EPO) and an EPO-related nonerythropoietic analog, pyroglutamate helix B surface peptide (pHBSP), were investigated in an in vitro model of bovine aortic endothelial cell injury under normoxic (21% O2) and hypoxic (1% O2) conditions. The potential molecular mechanisms of these effects were also explored. Using a model of endothelial injury (the scratch assay), we found that, under hypoxic conditions, EPO and pHBSP enhanced scratch closure by promoting cell migration and proliferation, but did not show any effect under normoxic conditions. Furthermore, EPO protected bovine aortic endothelial cells from staurosporine-induced apoptosis under hypoxic conditions. The priming effect of hypoxia was associated with stabilization of hypoxia inducible factor-1α, EPO receptor upregulation, and decreased Ser-1177 phosphorylation of endothelial nitric oxide synthase (NOS); the effect of hypoxia on the latter was rescued by EPO. Hypoxia was associated with a reduction in nitric oxide (NO) production as assessed by its oxidation products, nitrite and nitrate, consistent with the oxygen requirement for endogenous production of NO by endothelial NOS. However, while EPO did not affect NO formation in normoxia, it markedly increased NO production, in a manner sensitive to NOS inhibition, under hypoxic conditions. These data are consistent with the notion that the tissue-protective actions of EPO-related cytokines in pathophysiological settings associated with poor oxygenation are mediated by NO. These findings may be particularly relevant to atherogenesis and postangioplasty restenosis. PMID:27800514

  4. Endothelial cytoprotection from oxidized LDL by some crude Melanesian plant extracts is not related to their antioxidant capacity.

    PubMed

    Owen, Patrick L; Matainaho, Teatulohi; Sirois, Martin; Johns, Timothy

    2007-01-01

    Habitual consumption of some Melanesian medicinal and food plants may influence atherosclerosis development via their antioxidant capacity at the endothelial level. Areca nut (AN; Areca catechu), piper inflorescence (PBI; Piper betle), betel quid (BQ), guava buds (GB; Psidium guajava), the leaves (NL), juice (NJ), fruit (NF), and root (NR) of noni (Morinda citrifolia), the propagules of raw (MBR), and cooked (MBC) mangrove (Bruguiera gymnorrhiza) were evaluated for their ability to scavenge the 1,1-diphenyl-2-picryl-hydrazyle (DPPH) radical, to protect human low-density lipoprotein (LDL) from Cu2+-catalyzed oxidation and to protect cultured bovine aortal endothelial cells (BAEC) from oxidized LDL (oxLDL)-induced cytotoxicity. Polyphenol-rich extracts AN, PBI, and BQ were potent DPPH scavengers, having similar activity to quercetin and able to protect LDL from oxidation in a dose-dependent manner at concentrations higher than 10 microg/mL, but were pro-oxidants at lower concentrations. These extracts were cytotoxic to BAEC at concentrations above 10 microg/mL and were unable to prevent oxLDL endotheliopathy. GB and NR at 10 mug/mL displayed both the ability to delay LDL oxidation and prevent oxLDL cytotoxicity, although the latter lacked the ability to scavenge the DPPH radical. At higher concentrations, however, both were cytotoxic in themselves. The remaining noni extracts NF, NJ, NL, and both mangrove extracts MBC and MBR were unable to protect LDL from oxidation at all tested concentrations, but were effective cytoprotective agents at 50 microg/mL. All extracts were able to prevent an oxLDL-mediated increase in intracellular aldehyde generation but had little effect on extracellular peroxidation as measured by thiobarbituric acid reactive substances (TBARS). On the basis of this model system, we conclude that the antioxidant benefits of AN, PBI, and BQ may be offset by their enhancement of their cytotoxic effects of oxLDL toward BAEC, whereas GB and low

  5. Evaluation of kidney repair capacity using 99mTc-DMSA in ischemia/reperfusion injury models.

    PubMed

    Kwak, Wonjung; Jang, Hee-Seong; Belay, Takele; Kim, Jinu; Ha, Yeong Su; Lee, Sang Woo; Ahn, Byeong-Cheol; Lee, Jaetae; Park, Kwon Moo; Yoo, Jeongsoo

    2011-03-01

    Quantitative (99m)Tc-DMSA renal uptake was studied in different renal ischemia/reperfusion (I/R) mice models for the assessment of renal repair capacity. Mice models of nephrectomy, uni- and bi-lateral I/R together with sham-operated mice were established. At 1h, 1d, 4d, 1, 2 and 3 wk after I/R, (99m)Tc-DMSA (27.7 ± 1.3 MBq) was injected via tail vein and after 3h post-injection, the mice were scanned for 30 min with pinhole equipped gamma camera. Higher uptake of (99m)Tc-DMSA was measured in normal kidneys of uni-lateral I/R model and nephrectomized kidney I/R model at 3 wk post-surgery. Comparing the restoration capacities of the affected kidneys of nephrectomy, uni- and bi-lateral I/R models, higher repair capacity was observed in the nephrectomized model followed by bi-lateral then uni-lateral models. The normal kidney may retard the restoration of damaged kidney in uni-lateral I/R model. Moreover, 3 wk after Uni-I/R, the size of injured kidney was significantly smaller than non-ischemic contralateral and sham operated kidneys, while nephrectomy I/R kidneys were significantly enlarged compared to all others at 3 wk post-surgery. Very strong correlation between (99m)Tc-DMSA uptake and weight of dissected kidneys in I/R models was observed. Consistent with (99m)Tc-DMSA uptake results, all histological results indicate that kidney recovery after injury is correlated with the amount of intact tubules and kidney sizes. In summary, our study showed good potentials of (99m)Tc-DMSA scan as a promising non-invasive method for evaluation of kidney restoration after I/R injuries. Interestingly, mice with Bi-I/R injury showed faster repair capacity than those with uni-I/R.

  6. A novel strategy to enhance mesenchymal stem cell migration capacity and promote tissue repair in an injury specific fashion.

    PubMed

    Xinaris, C; Morigi, M; Benedetti, V; Imberti, B; Fabricio, A S; Squarcina, E; Benigni, A; Gagliardini, E; Remuzzi, G

    2013-01-01

    Mesenchymal stem cells (MSCs) of bone marrow origin appear to be an attractive candidate for cell-based therapies. However, the major barrier to the effective implementation of MSC-based therapies is the lack of specific homing of exogenously infused cells and overall the inability to drive them to the diseased or damaged tissue. In order to circumvent these limitations, we developed a preconditioning strategy to optimize MSC migration efficiency and potentiate their beneficial effect at the site of injury. Initially, we screened different molecules by using an in vitro injury-migration setting, and subsequently, we evaluated the effectiveness of the different strategies in mice with acute kidney injury (AKI). Our results showed that preconditioning of MSCs with IGF-1 before infusion improved cell migration capacity and restored normal renal function after AKI. The present study demonstrates that promoting migration of MSCs could increase their therapeutic potential and indicates a new therapeutic paradigm for organ repair.

  7. DNA repair capacity is impaired in healthy BRCA1 heterozygous mutation carriers.

    PubMed

    Vaclová, Tereza; Gómez-López, Gonzalo; Setién, Fernando; Bueno, José María García; Macías, José Antonio; Barroso, Alicia; Urioste, Miguel; Esteller, Manel; Benítez, Javier; Osorio, Ana

    2015-07-01

    BRCA1 germline mutations increase the lifetime risk of developing breast and ovarian cancers. However, taking into account the differences in disease manifestation among mutation carriers, it is probable that different BRCA1 mutations have distinct haploinsufficiency effects and lead to the formation of different phenotypes. Using lymphoblastoid cell lines derived from heterozygous BRCA1 mutation carriers and non-carriers, we investigated the haploinsufficiency effects of various mutation types using qPCR, immunofluorescence, and microarray technology. Lymphoblastoid cell lines carrying a truncating mutation showed significantly lower BRCA1 mRNA and protein levels and higher levels of gamma-H2AX than control cells or those harboring a missense mutation, indicating greater spontaneous DNA damage. Cells carrying either BRCA1 mutation type showed impaired RAD51 foci formation, suggesting defective repair in mutated cells. Moreover, compared to controls, cell lines carrying missense mutations displayed a more distinct expression profile than cells with truncating mutations, which is consistent with different mutations giving rise to distinct phenotypes. Alterations in the immune response pathway in cells harboring missense mutations point to possible mechanisms of breast cancer initiation in carriers of these mutations. Our findings offer insight into how various heterozygous mutations in BRCA1 could lead to impairment of BRCA1 function and provide strong evidence of haploinsufficiency in BRCA1 mutation carriers.

  8. Reduced DNA double-strand break repair capacity and risk of squamous cell carcinoma of the head and neck – A case-control study

    PubMed Central

    Liu, Zhensheng; Liu, Hongliang; Gao, Fengqin; Dahlstrom, Kristina R.; Sturgis, Erich M.; Wei, Qingyi

    2016-01-01

    Tobacco and alcohol use play important roles in the etiology of squamous cell carcinoma of the head and neck (SCCHN). Smoking causes DNA damage, including double-strand DNA breaks (DSBs), that leads to carcinogenesis. To test the hypothesis that suboptimal DSB repair capacity is associated with risk of SCCHN, we established a flow cytometry-based method to detect the DSB repair phenotype in four EBV-immortalized human lymphoblastoid cell lines and then in human peripheral blood T-lymphocytes (PBTLs). With this blood-based laboratory assay, we conducted a pilot case-control study of 100 patients with newly diagnosed, previously untreated SCCHN and 124 cancer-free controls of non-Hispanic whites. We found that the mean DSB repair capacity level (42.1) in cases was significantly lower than that in controls (54.4) (P < 0.001). When we used the median DSB repair capacity level in controls as the cutoff value for calculating the odds ratios (OR), after adjustment for age, sex, smoking and drinking status, the cases were more likely than the controls to have reduced DSB repair capacity (adjusted OR = 1.9; 95% confidence interval, CI = 1.0–3.6, P = 0.037), especially for cases who were ever drinkers (adjusted OR = 2.7; 95% CI = 1.2–6.4, P = 0.020) and had oropharyngeal tumors (adjusted OR = 2.2; 95% CI = 1.1–4.5, P = 0.035). In conclusion, these findings suggest that individuals with a reduced DSB repair capacity may be at an increased risk of developing SCCHN. Large studies are warranted to confirm these preliminary findings. PMID:26963119

  9. Reduced DNA double-strand break repair capacity and risk of squamous cell carcinoma of the head and neck--A case-control study.

    PubMed

    Liu, Zhensheng; Liu, Hongliang; Gao, Fengqin; Dahlstrom, Kristina R; Sturgis, Erich M; Wei, Qingyi

    2016-04-01

    Tobacco smoke and alcohol use play important roles in the etiology of squamous cell carcinoma of the head and neck (SCCHN). Smoking causes DNA damage, including double-strand DNA breaks (DSBs), that leads to carcinogenesis. To test the hypothesis that suboptimal DSB repair capacity is associated with risk of SCCHN, we applied a flow cytometry-based method to detect the DSB repair phenotype first in four EBV-immortalized human lymphoblastoid cell lines and then in human peripheral blood T-lymphocytes (PBTLs). With this blood-based laboratory assay, we conducted a pilot case-control study of 100 patients with newly diagnosed, previously untreated SCCHN and 124 cancer-free controls of non-Hispanic whites. We found that the mean DSB repair capacity level was significantly lower in cases (42.1%) than that in controls (54.4%) (P<0.001). When we used the median DSB repair capacity level in the controls as the cutoff value for calculating the odds ratios (ORs) with adjustment for age, sex, smoking and drinking status, the cases were more likely than the controls to have a reduced DSB repair capacity (adjusted OR=1.93; 95% confidence interval, CI=1.04-3.56, P=0.037), especially for those subjects who were ever drinkers (adjusted OR=2.73; 95% CI=1.17-6.35, P=0.020) and had oropharyngeal tumors (adjusted OR=2.17; 95% CI=1.06-4.45, P=0.035). In conclusion, these findings suggest that individuals with a reduced DSB repair capacity may be at an increased risk of developing SCCHN. Larger studies are warranted to confirm these preliminary findings. PMID:26963119

  10. Activation of the Notch signaling pathway promotes neurovascular repair after traumatic brain injury

    PubMed Central

    Ran, Qi-shan; Yu, Yun-hu; Fu, Xiao-hong; Wen, Yuan-chao

    2015-01-01

    The Notch signaling pathway plays a key role in angiogenesis and endothelial cell formation, but it remains unclear whether it is involved in vascular repair by endothelial progenitor cells after traumatic brain injury. Therefore, in the present study, we controlled the Notch signaling pathway using overexpression and knockdown constructs. Activation of the Notch signaling pathway by Notch1 or Jagged1 overexpression enhanced the migration, invasiveness and angiogenic ability of endothelial progenitor cells. Suppression of the Notch signaling pathway with Notch1 or Jagged1 siRNAs reduced the migratory capacity, invasiveness and angiogenic ability of endothelial progenitor cells. Activation of the Notch signaling pathway in vivo in a rat model of mild traumatic brain injury promoted neurovascular repair. These findings suggest that the activation of the Notch signaling pathway promotes blood vessel formation and tissue repair after brain trauma. PMID:26487853

  11. Correlation between PLD repair capacity and the survival curve of human fibroblasts in exponential growth phase: analysis in terms of several parameters

    SciTech Connect

    Fertil, B.; Deschavanne, P.J.; Debieu, D.; Malaise, E.P.

    1988-10-01

    Published data on the in vitro radiosensitivity of 46 nontransformed fibroblasts of different genetic origins studied in plateau phase with immediate or delayed plating were used to investigate to what extent potentially lethal damage repair capacity is related to intrinsic radiosensitivity (i.e., irradiated in exponential growth phase). While most of the survival curve analysis is conducted in terms of D0, Dq, and the mean inactivation dose D, some of the data are also discussed in terms of the linear-quadratic model parameter alpha. Using D it is shown that: (i) the radiosensitivity of human fibroblasts in exponential growth phase does not significantly differ from that of plateau-phase fibroblasts with immediate plating; (ii) the radiosensitivity of plateau-phase cells with delayed plating is correlated to the radiosensitivity of cells with immediate plating: the more radioresistant the cell strain in exponential growth phase, the higher its repair capacity; (iii) the repair capacity of the cell strains is related to their genetic origin. In conclusion, we suggest that the survival curve of growing cells depends on the repair capacity of the cells.

  12. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    USGS Publications Warehouse

    Kienzler, Aude; Mahler, Barbara J.; Van Metre, Peter C.; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-01-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

  13. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line.

    PubMed

    Kienzler, Aude; Mahler, Barbara J; Van Metre, Peter C; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-07-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

  14. Reduction in cardiolipin decreases mitochondrial spare respiratory capacity and increases glucose transport into and across human brain cerebral microvascular endothelial cells.

    PubMed

    Nguyen, Hieu M; Mejia, Edgard M; Chang, Wenguang; Wang, Ying; Watson, Emily; On, Ngoc; Miller, Donald W; Hatch, Grant M

    2016-10-01

    Microvessel endothelial cells form part of the blood-brain barrier, a restrictively permeable interface that allows transport of only specific compounds into the brain. Cardiolipin is a mitochondrial phospholipid required for function of the electron transport chain and ATP generation. We examined the role of cardiolipin in maintaining mitochondrial function necessary to support barrier properties of brain microvessel endothelial cells. Knockdown of the terminal enzyme of cardiolipin synthesis, cardiolipin synthase, in hCMEC/D3 cells resulted in decreased cellular cardiolipin levels compared to controls. The reduction in cardiolipin resulted in decreased mitochondrial spare respiratory capacity, increased pyruvate kinase activity, and increased 2-deoxy-[(3) H]glucose uptake and glucose transporter-1 expression and localization to membranes in hCMEC/D3 cells compared to controls. The mechanism for the increase in glucose uptake was an increase in adenosine-5'-monophosphate kinase and protein kinase B activity and decreased glycogen synthase kinase 3 beta activity. Knockdown of cardiolipin synthase did not affect permeability of fluorescent dextran across confluent hCMEC/D3 monolayers grown on Transwell(®) inserts. In contrast, knockdown of cardiolipin synthase resulted in an increase in 2-deoxy-[(3) H]glucose transport across these monolayers compared to controls. The data indicate that in hCMEC/D3 cells, spare respiratory capacity is dependent on cardiolipin. In addition, reduction in cardiolipin in these cells alters their cellular energy status and this results in increased glucose transport into and across hCMEC/D3 monolayers. Microvessel endothelial cells form part of the blood-brain barrier, a restrictively permeable interface that allows transport of only specific compounds into the brain. In human adult brain endothelial cell hCMEC/D3 monolayers cultured on Transwell(®) plates, knockdown of cardiolipin synthase results in decrease in mitochondrial

  15. Differences in DNA Repair Capacity, Cell Death and Transcriptional Response after Irradiation between a Radiosensitive and a Radioresistant Cell Line.

    PubMed

    Borràs-Fresneda, Mireia; Barquinero, Joan-Francesc; Gomolka, Maria; Hornhardt, Sabine; Rössler, Ute; Armengol, Gemma; Barrios, Leonardo

    2016-06-01

    Normal tissue toxicity after radiotherapy shows variability between patients, indicating inter-individual differences in radiosensitivity. Genetic variation probably contributes to these differences. The aim of the present study was to determine if two cell lines, one radiosensitive (RS) and another radioresistant (RR), showed differences in DNA repair capacity, cell viability, cell cycle progression and, in turn, if this response could be characterised by a differential gene expression profile at different post-irradiation times. After irradiation, the RS cell line showed a slower rate of γ-H2AX foci disappearance, a higher frequency of incomplete chromosomal aberrations, a reduced cell viability and a longer disturbance of the cell cycle when compared to the RR cell line. Moreover, a greater and prolonged transcriptional response after irradiation was induced in the RS cell line. Functional analysis showed that 24 h after irradiation genes involved in "DNA damage response", "direct p53 effectors" and apoptosis were still differentially up-regulated in the RS cell line but not in the RR cell line. The two cell lines showed different response to IR and can be distinguished with cell-based assays and differential gene expression analysis. The results emphasise the importance to identify biomarkers of radiosensitivity for tailoring individualized radiotherapy protocols.

  16. Differences in DNA Repair Capacity, Cell Death and Transcriptional Response after Irradiation between a Radiosensitive and a Radioresistant Cell Line

    PubMed Central

    Borràs-Fresneda, Mireia; Barquinero, Joan-Francesc; Gomolka, Maria; Hornhardt, Sabine; Rössler, Ute; Armengol, Gemma; Barrios, Leonardo

    2016-01-01

    Normal tissue toxicity after radiotherapy shows variability between patients, indicating inter-individual differences in radiosensitivity. Genetic variation probably contributes to these differences. The aim of the present study was to determine if two cell lines, one radiosensitive (RS) and another radioresistant (RR), showed differences in DNA repair capacity, cell viability, cell cycle progression and, in turn, if this response could be characterised by a differential gene expression profile at different post-irradiation times. After irradiation, the RS cell line showed a slower rate of γ-H2AX foci disappearance, a higher frequency of incomplete chromosomal aberrations, a reduced cell viability and a longer disturbance of the cell cycle when compared to the RR cell line. Moreover, a greater and prolonged transcriptional response after irradiation was induced in the RS cell line. Functional analysis showed that 24 h after irradiation genes involved in “DNA damage response”, “direct p53 effectors” and apoptosis were still differentially up-regulated in the RS cell line but not in the RR cell line. The two cell lines showed different response to IR and can be distinguished with cell-based assays and differential gene expression analysis. The results emphasise the importance to identify biomarkers of radiosensitivity for tailoring individualized radiotherapy protocols. PMID:27245205

  17. Modulation of DNA repair capacity and mRNA expression levels of XRCC1, hOGG1 and XPC genes in styrene-exposed workers

    SciTech Connect

    Hanova, Monika; Stetina, Rudolf; Vodickova, Ludmila; Vaclavikova, Radka; Hlavac, Pavel; Smerhovsky, Zdenek; Naccarati, Alessio; Polakova, Veronika; Soucek, Pavel; Kuricova, Miroslava; Manini, Paola; Kumar, Rajiv; Hemminki, Kari; Vodicka, Pavel

    2010-11-01

    Decreased levels of single-strand breaks in DNA (SSBs), reflecting DNA damage, have previously been observed with increased styrene exposure in contrast to a dose-dependent increase in the base-excision repair capacity. To clarify further the above aspects, we have investigated the associations between SSBs, micronuclei, DNA repair capacity and mRNA expression in XRCC1, hOGG1 and XPC genes on 71 styrene-exposed and 51 control individuals. Styrene concentrations at workplace and in blood characterized occupational exposure. The workers were divided into low (below 50 mg/m{sup 3}) and high (above 50 mg/m{sup 3}) styrene exposure groups. DNA damage and DNA repair capacity were analyzed in peripheral blood lymphocytes by Comet assay. The mRNA expression levels were determined by qPCR. A significant negative correlation was observed between SSBs and styrene concentration at workplace (R = - 0.38, p = 0.001); SSBs were also significantly higher in men (p = 0.001). The capacity to repair irradiation-induced DNA damage was the highest in the low exposure group (1.34 {+-} 1.00 SSB/10{sup 9} Da), followed by high exposure group (0.72 {+-} 0.81 SSB/10{sup 9} Da) and controls (0.65 {+-} 0.82 SSB/10{sup 9} Da). The mRNA expression levels of XRCC1, hOGG1 and XPC negatively correlated with styrene concentrations in blood and at workplace (p < 0.001) and positively with SSBs (p < 0.001). Micronuclei were not affected by styrene exposure, but were higher in older persons and in women (p < 0.001). In this study, we did not confirm previous findings on an increased DNA repair response to styrene-induced genotoxicity. However, negative correlations of SSBs and mRNA expression levels of XRCC1, hOGG1 and XPC with styrene exposure warrant further highly-targeted study.

  18. Cannabinoids inhibit angiogenic capacities of endothelial cells via release of tissue inhibitor of matrix metalloproteinases-1 from lung cancer cells.

    PubMed

    Ramer, Robert; Fischer, Sascha; Haustein, Maria; Manda, Katrin; Hinz, Burkhard

    2014-09-15

    Cannabinoids inhibit tumor neovascularization as part of their tumorregressive action. However, the underlying mechanism is still under debate. In the present study the impact of cannabinoids on potential tumor-to-endothelial cell communication conferring anti-angiogenesis was studied. Cellular behavior of human umbilical vein endothelial cells (HUVEC) associated with angiogenesis was evaluated by Boyden chamber, two-dimensional tube formation and fibrin bead assay, with the latter assessing three-dimensional sprout formation. Viability was quantified by the WST-1 test. Conditioned media (CM) from A549 lung cancer cells treated with cannabidiol, Δ(9)-tetrahydrocannabinol, R(+)-methanandamide or the CB2 agonist JWH-133 elicited decreased migration as well as tube and sprout formation of HUVEC as compared to CM of vehicle-treated cancer cells. Inhibition of sprout formation was further confirmed for cannabinoid-treated A549 cells co-cultured with HUVEC. Using antagonists to cannabinoid-activated receptors the antimigratory action was shown to be mediated via cannabinoid receptors or transient receptor potential vanilloid 1. SiRNA approaches revealed a cannabinoid-induced expression of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) as well as its upstream trigger, the intercellular adhesion molecule-1, to be causally linked to the observed decrease of HUVEC migration. Comparable anti-angiogenic effects were not detected following direct exposure of HUVEC to cannabinoids, but occurred after addition of recombinant TIMP-1 to HUVEC. Finally, antimigratory effects were confirmed for CM of two other cannabinoid-treated lung cancer cell lines (H460 and H358). Collectively, our data suggest a pivotal role of the anti-angiogenic factor TIMP-1 in intercellular tumor-endothelial cell communication resulting in anti-angiogenic features of endothelial cells.

  19. Diazoxide preconditioning of endothelial progenitor cells from streptozotocin-induced type 1 diabetic rats improves their ability to repair diabetic cardiomyopathy.

    PubMed

    Ali, Muhammad; Mehmood, Azra; Anjum, Muhammad Sohail; Tarrar, Moazzam Nazir; Khan, Shaheen N; Riazuddin, Sheikh

    2015-12-01

    Type 1 diabetes mellitus (DM) is a strong risk factor for the development of diabetic cardiomyopathy (DCM) which is the leading cause of morbidity and mortality in the type 1 diabetic patients. Stem cells may act as a therapeutic agent for the repair of DCM. However, deteriorated functional abilities and survival of stem cells derived from type 1 diabetic subjects need to be overcome for obtaining potential outcome of the stem cell therapy. Diazoxide (DZ) a highly selective mitochondrial ATP-sensitive K(+) channel opener has been previously shown to improve the ability of mesenchymal stem cells for the repair of heart failure. In the present study, we evaluated the effects of DZ preconditioning in improving the ability of streptozotocin-induced type 1 diabetes affected bone marrow-derived endothelial progenitor cells (DM-EPCs) for the repair of DCM in the type 1 diabetic rats. DM-EPCs were characterized by immunocytochemistry, flow cytometry, and reverse transcriptase PCR for endothelial cell-specific markers like vWF, VE cadherin, VEGFR2, PECAM, CD34, and eNOS. In vitro studies included preconditioning of DM-EPCs with 200 μM DZ for 30 min followed by exposure to either 200 μM H2O2 for 2 h (for oxidative stress induction) or 30 mM glucose media (for induction of hyperglycemic stress) for 48 h. Non-preconditioned EPCs with and without exposure to H2O2 and 30 mM high glucose served as controls. These cells were then evaluated for survival (by MTT and XTT cell viability assays), senescence, paracrine potential (by ELISA for VEGF), and alteration in gene expression [VEGF, stromal derived factor-1α (SDF-1α), HGF, bFGF, Bcl2, and Caspase-3]. DZ preconditioned DM-EPCs demonstrated significantly increased survival and VEGF release while reduced cell injury and senescence. Furthermore, DZ preconditioned DM-EPCs exhibited up-regulated expression of prosurvival genes (VEGF, SDF-1α, HGF, bFGF, and Bcl2) on exposure to H2O2, and VEGF and Bcl2 on exposure to hyperglycemia

  20. DNA repair capacity of cultured human lymphocytes exposed to mutagens measured by the comet assay and array expression analysis.

    PubMed

    Bausinger, Julia; Speit, Günter

    2015-11-01

    Repair of mutagen-induced DNA lesions during transportation, storage and cultivation of lymphocytes may have a significant impact on results obtained in human biomonitoring after occupational and environmental exposure of human populations to genotoxic chemicals. Using the comet assay in combination with the repair inhibitor aphidicolin and array gene expression analysis of 92 DNA repair genes, we investigated the repair of DNA lesions induced by methyl methanesulfonate (MMS) and benzo[a]pyrenediolepoxide (BPDE) in phytohaemagglutinin (PHA)-stimulated cultured human lymphocytes in the time segment before replication. The comet assay indicated fast repair of MMS-induced damage during the first hours of cultivation. In contrast, removal of BPDE-induced lesions was slower and significant amounts of damage seem to persist until S-phase. Gene expression analysis revealed that PHA stimulation had a clear effect on gene regulation in lymphocytes already during the first 18h of cultivation. Under the conditions of this study, genotoxic concentrations of MMS did not induce significant changes in gene expression. In contrast, exposure to BPDE led to altered expression of several genes in a time- and concentration-related manner. Of the significantly up-regulated genes, only two genes (XPA and XPC) were directly related to nucleotide excision repair. Our results suggest that PHA stimulation of human lymphocytes influences the expression of DNA repair genes in human lymphocytes. The effect of induced DNA damage on gene expression is comparatively low and depends on the mutagens used. PHA-stimulated lymphocytes repair induced DNA damage before they start to replicate but the repair activity during the first 18h of cultivation is not affected by changes in the expression of DNA repair genes during this period of time.

  1. Self-Renewal and High Proliferative Colony Forming Capacity of Late-Outgrowth Endothelial Progenitors Is Regulated by Cyclin-Dependent Kinase Inhibitors Driven by Notch Signaling.

    PubMed

    Patel, Jatin; Wong, Ho Yi; Wang, Weili; Alexis, Josue; Shafiee, Abbas; Stevenson, Alexander J; Gabrielli, Brian; Fisk, Nicholas M; Khosrotehrani, Kiarash

    2016-04-01

    Since the discovery of endothelial colony forming cells (ECFC), there has been significant interest in their therapeutic potential to treat vascular injuries. ECFC cultures display significant heterogeneity and a hierarchy among cells able to give rise to high proliferative versus low proliferative colonies. Here we aimed to define molecularly this in vitro hierarchy. Based on flow cytometry, CD34 expression levels distinguished two populations. Only CD34 + ECFC had the capacity to reproduce high proliferative potential (HPP) colonies on replating, whereas CD34- ECFCs formed only small clusters. CD34 + ECFCs were the only ones to self-renew in stringent single-cell cultures and gave rise to both CD34 + and CD34- cells. Upon replating, CD34 + ECFCs were always found at the centre of HPP colonies and were more likely in G0/1 phase of cell cycling. Functionally, CD34 + ECFC were superior at restoring perfusion and better engrafted when injected into ischemic hind limbs. Transcriptomic analysis identified cyclin-dependent kinase (CDK) cell cycle inhibiting genes (p16, p21, and p57), the Notch signaling pathway (dll1, dll4, hes1, and hey1), and the endothelial cytokine il33 as highly expressed in CD34 + ECFC. Blocking the Notch pathway using a γ-secretase inhibitor (DAPT) led to reduced expression of cell cycle inhibitors, increased cell proliferation followed by a loss of self-renewal, and HPP colony formation capacity reflecting progenitor exhaustion. Similarly shRNA knockdown of p57 strongly affected self-renewal of ECFC colonies. ECFC hierarchy is defined by Notch signalling driving cell cycle regulators, progenitor quiescence and self-renewal potential. PMID:26732848

  2. DNA damage and repair capacity by comet assay in lymphocytes of white-collar active smokers and passive smokers (non- and ex-smokers) at workplace.

    PubMed

    Fracasso, Maria Enrica; Doria, Denise; Franceschetti, Paola; Perbellini, Luigi; Romeo, Luciano

    2006-12-01

    The comet assay has been widely used to quantify DNA damage in isolated lymphocytes from subjects exposed to several environmental or occupational substances, especially for estimation of oxidative damage in the DNA, which is well-known to be induced by tobacco smoke. Passive smoking or environmental tobacco smoke (ETS) has been included among those substances that cause cancer with sufficient evidence in humans. In this study, we analyzed, by the alkaline version of comet assay, the lymphocyte DNA damage of white-collar active smokers and non- and ex-smokers exposed to ETS at the workplace. We investigated basal DNA damage, DNA oxidation by formamidopyrimidine glycosylase (Fpg), the repair capacity H2O2-induced DNA damage by kinetics studies and lymphocyte GSH levels, the major intracellular defense against exogenous oxidative stress imposed by cigarette smoking. Our results indicated high basal DNA damage with clear significant correlations with urinary nicotine and cotinine, number of cigarettes/day, and an inverse significant correlation with GSH cellular content in active smokers. Significant Fpg-sensitive sites were found in smokers (> 85%), considerably high but not significant in passive non- and ex-smokers (> 51% and 37%, respectively). The DNA repair capacity had seriously decreased in non-smokers > smokers > ex-smokers, while the same damage was repaired in a short time in never smokers. PMID:17027201

  3. Vascular endothelial cells have impaired capacity to present immunodominant, antigenic peptides: a mechanism of cell type-specific immune escape.

    PubMed

    Kummer, Marco; Lev, Avital; Reiter, Yoram; Biedermann, Barbara C

    2005-02-15

    Vascular endothelial cells (EC) are an exposed target tissue in the course of CTL-mediated alloimmune diseases such as graft-vs-host disease (GVHD) or solid organ transplant rejection. The outcome of an interaction between CTL and target cells is determined by the amount of Ag presented and the costimulatory signals delivered by the target cells. We compared human EC with leukocytes and epithelial cells as targets for peptide-specific, MHC class I-restricted CTL clones. EC were poor targets for immunodominant CTL. Both endogenously processed antigenic proteins and exogenously added antigenic peptides are presented at 50- to 5000-fold lower levels on EC compared with any other target cell analyzed. This quantitative difference fully explained the poor CTL-mediated killing of EC. There was no evidence that lack of costimulation would contribute significantly to this cell type-specific difference in CTL activation. An HLA-A2-specific CTL clone that killed a broad selection of HLA A2-positive target cells equally well, killed EC less efficiently. Our data suggest that EC present a different Ag repertoire compared with other cell types. By this mechanism, these cells may escape an attack by effector CTL, which have been educated by professional APCs and are specific for immunodominant antigenic peptides. PMID:15699122

  4. Loss of p21WAF1/Cip1 in Gadd45-deficient keratinocytes restores DNA repair capacity.

    PubMed

    Maeda, Tomoko; Espino, Robin A; Chomey, Eugene G; Luong, Le; Bano, Ather; Meakins, Diana; Tron, Victor A

    2005-10-01

    Ultraviolet light (UV)-induced DNA damage is repaired primarily by the nucleotide excision repair (NER) pathway. Gadd45 is a multifunctional protein that regulates NER. Gadd45-deficient keratinocytes fail to repair UV-induced DNA damage, but the mechanism by which Gadd45 stimulates repair of UV-induced DNA damage is unknown. p21WAF1/Cip1 (p21) is a well-characterized downstream target of p53 that binds to Gadd45 and proliferating cell nuclear antigen (PCNA). The role of p21 in NER is somewhat controversial, however, recent studies appear to suggest that it inhibits DNA repair by inhibiting PCNA activity. Since a physical interplay exists between p21, Gadd45 and PCNA, we hypothesized that Gadd45 promoted DNA repair via p21. Initially, we examined p21 protein expression in Gadd45-deficient and proficient mice and found a higher base level of p21 protein in Gadd45-deficient keratinocytes and in most other tissues. With these results, we next speculated on the role played by p21 in Gadd45 regulated NER, by exposing keratinocytes from wild-type, single and double knockout (Gadd45 and p21) mice to UV, and measuring the responses. We confirmed that Gadd45-deficient keratinocytes were defective in UV-induced NER, but interestingly Gadd45/p21-null keratinocytes had normal NER in response to UV. Furthermore, Gadd45/p21-null keratinocytes were more resistant to UV-induced cell death than Gadd45-deficient keratinocytes. These results support the hypothesis that Gadd45 enhances NER by negatively regulating basal p21 expression in keratinocytes. PMID:15917306

  5. CD34 expression modulates tube-forming capacity and barrier properties of peripheral blood-derived endothelial colony-forming cells (ECFCs).

    PubMed

    Tasev, Dimitar; Konijnenberg, Lara S F; Amado-Azevedo, Joana; van Wijhe, Michiel H; Koolwijk, Pieter; van Hinsbergh, Victor W M

    2016-07-01

    Endothelial colony-forming cells (ECFC) are grown from circulating CD34(+) progenitors present in adult peripheral blood, but during in vitro expansion part of the cells lose CD34. To evaluate whether the regulation of CD34 characterizes the angiogenic phenotypical features of PB-ECFCs, we investigated the properties of CD34(+) and CD34(-) ECFCs with respect to their ability to form capillary-like tubes in 3D fibrin matrices, tip-cell gene expression, and barrier integrity. Selection of CD34(+) and CD34(-) ECFCs from subcultured ECFCs was accomplished by magnetic sorting (FACS: CD34(+): 95 % pos; CD34(-): 99 % neg). Both fractions proliferated at same rate, while CD34(+) ECFCs exhibited higher tube-forming capacity and tip-cell gene expression than CD3(4-) cells. However, during cell culture CD34(-) cells re-expressed CD34. Cell-seeding density, cell-cell contact formation, and serum supplements modulated CD34 expression. CD34 expression in ECFCs was strongly suppressed by newborn calf serum. Stimulation with FGF-2, VEGF, or HGF prepared in medium supplemented with 3 % albumin did not change CD34 mRNA or surface expression. Silencing of CD34 with siRNA resulted in strengthening of cell-cell contacts and increased barrier function of ECFC monolayers as measured by ECIS. Furthermore, CD34 siRNA reduced tube formation by ECFC, but did not affect tip-cell gene expression. These findings demonstrate that CD34(+) and CD34(-) cells are different phenotypes of similar cells and that CD34 (1) can be regulated in ECFC; (2) is positively involved in capillary-like sprout formation; (3) is associated but not causally related to tip-cell gene expression; and (4) can affect endothelial barrier function. PMID:27043316

  6. Mechanisms of stress resistance in Snell dwarf mouse fibroblasts: enhanced antioxidant and DNA base excision repair capacity, but no differences in mitochondrial metabolism.

    PubMed

    Page, Melissa M; Salmon, Adam B; Leiser, Scott F; Robb, Ellen L; Brown, Melanie F; Miller, Richard A; Stuart, Jeffrey A

    2009-04-15

    Dermal fibroblasts from long-lived Snell dwarf mice can withstand a variety of oxidative and non-oxidative stressors compared to normal littermate controls. Here, we report differences in the levels and activities of intracellular antioxidant and DNA repair enzymes between normal and Snell dwarf mice fibroblasts cultured under a variety of conditions, including: 3% and 20% ambient O(2); the presence and absence of serum; and the addition of an exogenous oxidative stress. The only significant difference between normal and dwarf cells cultured in complete medium, at 20% O(2), was an approximately 40% elevation of glutathione peroxidase (GPx) activity in the mutant cells. Serum deprivation elicited increases in GPx in both genotypes, but these activities remained higher in dwarf mouse cells. Dwarf mouse cells deprived of serum and challenged with exposure to paraquat or hydrogen peroxide showed a generally greater upregulation of catalase and DNA base excision repair enzymes. As these toxins can interact with mitochondria to increase mitochondrial ROS production, we explored whether there were differences in mitochondrial metabolism between normal and dwarf mouse cells. However, neither mitochondrial content nor the apparent mitochondrial membrane potential differed between genotypes. Overall, the results suggest that superior hydrogen peroxide metabolism and a marginally greater DNA base excision repair capacity contribute to the stress resistance phenotype of Snell dwarf mouse fibroblasts.

  7. Mechanisms of stress resistance in Snell dwarf mouse fibroblasts: enhanced antioxidant and DNA base excision repair capacity, but no differences in mitochondrial metabolism.

    PubMed

    Page, Melissa M; Salmon, Adam B; Leiser, Scott F; Robb, Ellen L; Brown, Melanie F; Miller, Richard A; Stuart, Jeffrey A

    2009-04-15

    Dermal fibroblasts from long-lived Snell dwarf mice can withstand a variety of oxidative and non-oxidative stressors compared to normal littermate controls. Here, we report differences in the levels and activities of intracellular antioxidant and DNA repair enzymes between normal and Snell dwarf mice fibroblasts cultured under a variety of conditions, including: 3% and 20% ambient O(2); the presence and absence of serum; and the addition of an exogenous oxidative stress. The only significant difference between normal and dwarf cells cultured in complete medium, at 20% O(2), was an approximately 40% elevation of glutathione peroxidase (GPx) activity in the mutant cells. Serum deprivation elicited increases in GPx in both genotypes, but these activities remained higher in dwarf mouse cells. Dwarf mouse cells deprived of serum and challenged with exposure to paraquat or hydrogen peroxide showed a generally greater upregulation of catalase and DNA base excision repair enzymes. As these toxins can interact with mitochondria to increase mitochondrial ROS production, we explored whether there were differences in mitochondrial metabolism between normal and dwarf mouse cells. However, neither mitochondrial content nor the apparent mitochondrial membrane potential differed between genotypes. Overall, the results suggest that superior hydrogen peroxide metabolism and a marginally greater DNA base excision repair capacity contribute to the stress resistance phenotype of Snell dwarf mouse fibroblasts. PMID:19439226

  8. Human resident CD34+ stromal cells/telocytes have progenitor capacity and are a source of αSMA+ cells during repair.

    PubMed

    Díaz-Flores, L; Gutiérrez, R; García, M P; González, M; Sáez, F J; Aparicio, F; Díaz-Flores, L; Madrid, J F

    2015-05-01

    We studied the progenitor capacity of human resident CD34+ stromal cells/telocytes (SC/TCs) in the enteric wall affected by inflammatory/repair processes (appendicitis, diverticulitis of large bowel and Crohn's disease of the terminal ileum) at different stages of evolution (inflammatory, proliferative and remodelling). In these conditions, CD34+ SC/TCs are activated, showing changes, which include the following overlapping events: 1) separation from adjacent structures (e.g., from vascular walls) and location in oedematous spaces, 2) morphological modifications (in cell shape and size) with presence of transitional cell forms between quiescent and activated CD34+ SC/TCs, 3) rapid proliferation and 4) loss of CD34 expression and gain of αSMA expression. These events mainly occur in the inflammatory and proliferative stages. During the loss of CD34 expression, the following findings are observed: a) irregular cell labelling intensity for anti-CD34, b) co-localization of CD34 and actin, c) concurrent irregular labelling intensity for αSMA and d) αSMA expression in all stromal cells, with total loss of CD34 expression. While CD34 expression was conserved, a high proliferative capacity (Ki-67 expression) was observed and vice versa. In the segments of the ileum affected by Crohn's disease, the stromal cells around fissures were αSMA+ and, in the transitional zones with normal enteric wall, activated CD34+ SC/TCs were observed. In conclusion, human resident CD34+ SC/TCs in the enteric wall have progenitor capacity and are activated with or without differentiation into αSMA+ stromal cells during inflammatory/repair processes.

  9. Transfusion of CXCR4-primed endothelial progenitor cells reduces cerebral ischemic damage and promotes repair in db/db diabetic mice.

    PubMed

    Chen, Ji; Chen, Jianying; Chen, Shuzhen; Zhang, Cheng; Zhang, Liangqing; Xiao, Xiang; Das, Avik; Zhao, Yuhui; Yuan, Bin; Morris, Mariana; Zhao, Bin; Chen, Yanfang

    2012-01-01

    This study investigated the role of stromal cell-derived factor-1α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) axis in brain and endothelial progenitor cells (EPCs), and explored the efficacy of CXCR4 primed EPCs in treating ischemic stroke in diabetes. The db/db diabetic and db/+ mice were used in this study. Levels of plasma SDF-1α and circulating CD34+CXCR4+ cells were measured. Brain SDF-1α and CXCR4 expression were quantified at basal and after middle cerebral artery occlusion (MCAO). In in vitro study, EPCs were transfected with adenovirus carrying null (Ad-null) or CXCR4 (Ad-CXCR4) followed with high glucose (HG) treatment for 4 days. For pathway block experiments, cells were pre-incubated with PI3K inhibitor or nitric oxide synthase (NOS) inhibitor for two hours. The CXCR4 expression, function and apoptosis of EPCs were determined. The p-Akt/Akt and p-eNOS/eNOS expression in EPCs were also measured. In in vivo study, EPCs transfected with Ad-null or Ad-CXCR4 were infused into mice via tail vein. On day 2 and 7, the cerebral blood flow, neurologic deficit score, infarct volume, cerebral microvascular density, angiogenesis and neurogenesis were determined. We found: 1) The levels of plasma SDF-1α and circulating CD34+CXCR4+ cells were decreased in db/db mice; 2) The basal level of SDF-1α and MCAO-induced up-regulation of SDF-1α/CXCR4 axis were reduced in the brain of db/db mice; 3) Ad-CXCR4 transfection increased CXCR4 expression in EPCs and enhanced EPC colonic forming capacity; 4) Ad-CXCR4 transfection prevented EPCs from HG-induced dysfunction (migration and tube formation) and apoptosis via activation of PI3K/Akt/eNOS signal pathway; 4) Ad-CXCR4 transfection enhanced the efficacy of EPC infusion in attenuating infarct volume and promoting angiogenesis and neurogenesis. Our data suggest that Ad-CXCR4 primed EPCs have better therapeutic effects for ischemia stroke in diabetes than unmodified EPCs do. PMID:23185548

  10. Copper-doped borosilicate bioactive glass scaffolds with improved angiogenic and osteogenic capacity for repairing osseous defects.

    PubMed

    Zhao, Shichang; Wang, Hui; Zhang, Yadong; Huang, Wenhai; Rahaman, Mohamed N; Liu, Zhongtang; Wang, Deping; Zhang, Changqing

    2015-03-01

    There is growing interest in the use of synthetic biomaterials to deliver inorganic ions that are known to stimulate angiogenesis and osteogenesis in vivo. In the present study, we investigated the effects of varying amounts of copper in a bioactive glass on the response of human bone marrow-derived mesenchymal stem cells (hBMSCs) in vitro and on blood vessel formation and bone regeneration in rat calvarial defects in vivo. Porous scaffolds of a borosilicate bioactive glass (composition 6Na2O, 8K2O, 8MgO, 22CaO, 36B2O3, 18SiO2, 2P2O5, mol.%) doped with 0.5, 1.0 and 3.0wt.% CuO were created using a foam replication method. When immersed in simulated body fluid, the scaffolds released Cu ions into the medium and converted to hydroxyapatite. At the concentrations used, the Cu in the glass was not toxic to the hBMSCs cultured on the scaffolds in vitro. The alkaline phosphatase activity of the hBMSCs and the expression levels of angiogenic-related genes (vascular endothelial growth factor and basic fibroblast growth factor) and osteogenic-related genes (runt-related transcription factor 2, bone morphogenetic protein-2 and osteopontin) increased significantly with increasing amount of Cu in the glass. When implanted in rat calvarial defects in vivo, the scaffolds (3wt.% CuO) significantly enhanced both blood vessel formation and bone regeneration in the defects at 8weeks post-implantation. These results show that doping bioactive glass implants with Cu is a promising approach for enhancing angiogenesis and osteogenesis in the healing of osseous defects.

  11. Cardiac regeneration: epicardial mediated repair

    PubMed Central

    2015-01-01

    The hearts of lower vertebrates such as fish and salamanders display scarless regeneration following injury, although this feature is lost in adult mammals. The remarkable capacity of the neonatal mammalian heart to regenerate suggests that the underlying machinery required for the regenerative process is evolutionarily retained. Recent studies highlight the epicardial covering of the heart as an important source of the signalling factors required for the repair process. The developing epicardium is also a major source of cardiac fibroblasts, smooth muscle, endothelial cells and stem cells. Here, we examine animal models that are capable of scarless regeneration, the role of the epicardium as a source of cells, signalling mechanisms implicated in the regenerative process and how these mechanisms influence cardiomyocyte proliferation. We also discuss recent advances in cardiac stem cell research and potential therapeutic targets arising from these studies. PMID:26702046

  12. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus.

    PubMed

    Reynolds, John A; Haque, Sahena; Williamson, Kate; Ray, David W; Alexander, M Yvonne; Bruce, Ian N

    2016-01-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk. PMID:26930567

  13. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus.

    PubMed

    Reynolds, John A; Haque, Sahena; Williamson, Kate; Ray, David W; Alexander, M Yvonne; Bruce, Ian N

    2016-03-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk.

  14. Vitamin D improves endothelial dysfunction and restores myeloid angiogenic cell function via reduced CXCL-10 expression in systemic lupus erythematosus

    PubMed Central

    Reynolds, John A.; Haque, Sahena; Williamson, Kate; Ray, David W.; Alexander, M. Yvonne; Bruce, Ian N.

    2016-01-01

    Patients with systemic lupus erythematosus (SLE) have accelerated cardiovascular disease and dysfunctional endothelial repair mechanisms. Myeloid angiogenic cells (MACs), derived from circulating monocytes, augment vascular repair by paracrine secretion of pro-angiogenic factors. We observed that SLE MACs are dysfunctional and secrete pro-inflammatory cytokines. We also found that the vitamin D receptor was transiently expressed during MAC differentiation and that in vitro, calcitriol increased differentiation of monocytes into MACs in both SLE and in a model using the prototypic SLE cytokine, interferon-alpha. The active form of vitamin D (calcitriol) restored the SLE MAC phenotype towards that of healthy subjects with reduced IL-6 secretion, and normalised surface marker expression. Calcitriol also augmented the angiogenic capacity of MACs via the down-regulation of CXCL-10. In SLE patients treated with cholecalciferol for 12 weeks, the improvement in endothelial function correlated with increase in serum 25(OH)D concentrations independently of disease activity. We also show that MACs were able to positively modulate eNOS expression in human endothelial cells in vitro, an effect further enhanced by calcitriol treatment of SLE MACs. The results demonstrate that vitamin D can positively modify endothelial repair mechanisms and thus endothelial function in a population with significant cardiovascular risk. PMID:26930567

  15. Expression and regulation of vascular endothelial growth factor ligands and receptors during menstruation and post-menstrual repair of human endometrium.

    PubMed

    Punyadeera, C; Thijssen, V L; Tchaikovski, S; Kamps, R; Delvoux, B; Dunselman, G A J; de Goeij, A F P M; Griffioen, A W; Groothuis, P G

    2006-06-01

    Regeneration and growth of the human endometrium after shedding of the functional layer during menstruation depends on an adequate angiogenic response. We analysed the mRNA expression levels of all known vascular endothelial growth factor (VEGF) ligands and receptors in human endometrium collected in the menstrual and proliferative phases of the menstrual cycle. In addition, we evaluated the expression of VEGF-A, VEGF-R2 and NRP-1 at the protein level. Two periods of elevated mRNA expression of ligands and receptors were observed, separated by a distinct drop at cycle days (CDs) 9 and 10. Immunohistochemical staining showed that VEGF and VEGF-R2 were expressed in epithelial, stromal and endothelial cells. NRP-1 was mainly confined to stroma and blood vessels; only in late-proliferative endometrium, epithelial staining was also observed. Except for endothelial VEGF-R2 expression in CDs 6-8, there were no significant differences in the expression of VEGF, VEGF-R2 or NRP-1 in any of the cell compartments. In contrast, VEGF release by cultured human endometrium explants decreased during the proliferative phase. This output was significantly reduced in menstrual and early-proliferative endometrium by estradiol (E2) treatment. Western blot analysis indicated that part of the VEGF-A was trapped in the extracellular matrix (ECM). Changes in VEGF ligands and receptors were associated with elevated expression of the hypoxia markers HIF1alpha and CA-IX in the menstrual and early proliferative phases. HIF1alpha was also detected in late-proliferative phase endometrium. Our findings indicate that VEGF-A exerts its actions mostly during the first half of the proliferative phase. Furthermore, VEGF-A production appears to be triggered by hypoxia in the menstrual phase and subsequently suppressed by estrogen during the late proliferative phase.

  16. Mononuclear cells and vascular repair in HHT

    PubMed Central

    Dingenouts, Calinda K. E.; Goumans, Marie-José; Bakker, Wineke

    2015-01-01

    Hereditary hemorrhagic telangiectasia (HHT) or Rendu–Osler–Weber disease is a rare genetic vascular disorder known for its endothelial dysplasia causing arteriovenous malformations and severe bleedings. HHT-1 and HHT-2 are the most prevalent variants and are caused by heterozygous mutations in endoglin and activin receptor-like kinase 1, respectively. An undervalued aspect of the disease is that HHT patients experience persistent inflammation. Although endothelial and mural cells have been the main research focus trying to unravel the mechanism behind the disease, wound healing is a process with a delicate balance between inflammatory and vascular cells. Inflammatory cells are part of the mononuclear cells (MNCs) fraction, and can, next to eliciting an immune response, also have angiogenic potential. This biphasic effect of MNC can hold a promising mechanism to further elucidate treatment strategies for HHT patients. Before MNC are able to contribute to repair, they need to home to and retain in ischemic and damaged tissue. Directed migration (homing) of MNCs following tissue damage is regulated by the stromal cell derived factor 1 (SDF1). MNCs that express the C-X-C chemokine receptor 4 (CXCR4) migrate toward the tightly regulated gradient of SDF1. This directed migration of monocytes and lymphocytes can be inhibited by dipeptidyl peptidase 4 (DPP4). Interestingly, MNC of HHT patients express elevated levels of DPP4 and show impaired homing toward damaged tissue. Impaired homing capacity of the MNCs might therefore contribute to the impaired angiogenesis and tissue repair observed in HHT patients. This review summarizes recent studies regarding the role of MNCs in the etiology of HHT and vascular repair, and evaluates the efficacy of DPP4 inhibition in tissue integrity and repair. PMID:25852751

  17. DNA Repair Capacity in Peripheral Lymphocytes Predicts Survival of Patients With Non–Small-Cell Lung Cancer Treated With First-Line Platinum-Based Chemotherapy

    PubMed Central

    Wang, Li-E; Yin, Ming; Dong, Qiong; Stewart, David J.; Merriman, Kelly W.; Amos, Christopher I.; Spitz, Margaret R.; Wei, Qingyi

    2011-01-01

    Purpose Platinum-based regimens are the standard chemotherapy for patients with advanced non–small-cell lung cancer (NSCLC). DNA repair capacity (DRC) in tumor cells plays an important role in resistance to platinum-based drugs. We have previously reported that efficient DRC, as assessed by an in vitro lymphocyte-based assay, was a determinant of poor survival in patients with NSCLC in a relatively small data set. In this larger independent study of 591 patients with NSCLC, we further evaluated whether DRC in peripheral lymphocytes predicts survival of patients with NSCLC who receive platinum-based chemotherapy. Patients and Methods All patients were recruited at The University of Texas MD Anderson Cancer Center and donated blood samples before the start of any chemotherapy. We measured DRC in cultured T lymphocytes by using the host-cell reactivation assay, and we assessed associations between DRC in peripheral lymphocytes and survival of patients with NSCLC who were treated with first-line platinum-based chemotherapy. Results We found an inverse association between DRC in peripheral lymphocytes and patient survival. Compared with patients in the low tertile of DRC, patients with NSCLC in the high tertile of DRC had significantly worse overall and 3-year survival (adjusted hazard ratio [HR], 1.33; 95% CI, 1.04 to 1.71; P = .023; and HR, 1.35; 95% CI, 1.04 to 1.76; P = .025, respectively). This trend was more pronounced in patients with early-stage tumors, adenocarcinoma, or squamous cell carcinoma. Conclusion We confirmed that DRC in peripheral lymphocytes is an independent predictor of survival for patients with NSCLC treated with platinum-based chemotherapy. PMID:21947825

  18. Establishment of a non-radioactive cleavage assay to assess the DNA repair capacity towards oxidatively damaged DNA in subcellular and cellular systems and the impact of copper.

    PubMed

    Hamann, Ingrit; Schwerdtle, Tanja; Hartwig, Andrea

    2009-10-01

    Oxidative stress is involved in many diseases, and the search for appropriate biomarkers is one major focus in molecular epidemiology. 8-Oxoguanine (8-oxoG), a potentially mutagenic DNA lesion, is considered to be a sensitive biomarker for oxidative stress. Another approach consists in assessing the repair capacity towards 8-oxoG, mediated predominantly by the human 8-oxoguanine DNA glycosylase 1 (hOGG1). With respect to the latter, during the last few years so-called cleavage assays have been described, investigating the incision of (32)P-labelled and 8-oxoG damaged oligonucleotides by cell extracts. Within the present study, a sensitive non-radioactive test system based on a Cy5-labelled oligonucleotide has been established. Sources of incision activity are isolated proteins or extracts prepared from cultured cells and peripheral blood mononuclear cells (PBMC). After comparing different oligonucleotide structures, a hairpin-like structure was selected which was not degraded by cell extracts. Applying this test system the impact of copper on the activity of isolated hOGG1 and on hOGG activity in A549 cells was examined, showing a distinct inhibition of the isolated protein at low copper concentration as compared to a modest inhibition of hOGG activity in cells at beginning cytotoxic concentrations. For investigating PBMC, all reaction conditions, including the amounts of oligonucleotide and cell extract as well as the reaction time have been optimized. The incision activities of PBMC protein extracts obtained from different donors have been investigated, and inter-individual differences have been observed. In summary, the established method is as sensitive and even faster than the radioactive technique, and additionally, offers the advantage of reduced costs and low health risk. PMID:19505484

  19. Myeloperoxidase Oxidized LDL Interferes with Endothelial Cell Motility through miR-22 and Heme Oxygenase 1 Induction: Possible Involvement in Reendothelialization of Vascular Injuries

    PubMed Central

    Daher, Jalil; Martin, Maud; Rousseau, Alexandre; Nuyens, Vincent; Fayyad-Kazan, Hussein; Van Antwerpen, Pierre; Courbebaisse, Guy; Martiat, Philippe; Badran, Bassam; Dequiedt, Frank

    2014-01-01

    Cardiovascular disease linked to atherosclerosis is the leading cause of death worldwide. Atherosclerosis is mainly linked to dysfunction in vascular endothelial cells and subendothelial accumulation of oxidized forms of LDL. In the present study, we investigated the role of myeloperoxidase oxidized LDL (Mox-LDL) in endothelial cell dysfunction. We studied the effect of proinflammatory Mox-LDL treatment on endothelial cell motility, a parameter essential for normal vascular processes such as angiogenesis and blood vessel repair. This is particularly important in the context of an atheroma plaque, where vascular wall integrity is affected and interference with its repair could contribute to progression of the disease. We investigated in vitro the effect of Mox-LDL on endothelial cells angiogenic properties and we also studied the signalling pathways that could be affected by analysing Mox-LDL effect on the expression of angiogenesis-related genes. We report that Mox-LDL inhibits endothelial cell motility and tubulogenesis through an increase in miR-22 and heme oxygenase 1 expression. Our in vitro data indicate that Mox-LDL interferes with parameters associated with angiogenesis. They suggest that high LDL levels in patients would impair their endothelial cell capacity to cope with a damaged endothelium contributing negatively to the progression of the atheroma plaque. PMID:25530680

  20. Mesenchymal-endothelial-transition contributes to cardiac neovascularization

    PubMed Central

    Ubil, Eric; Duan, Jinzhu; Pillai, Indulekha C.L.; Rosa-Garrido, Manuel; Wu, Yong; Bargiacchi, Francesca; Lu, Yan; Stanbouly, Seta; Huang, Jie; Rojas, Mauricio; Vondriska, Thomas M.; Stefani, Enrico; Deb, Arjun

    2014-01-01

    Endothelial cells contribute to a subset of cardiac fibroblasts by undergoing endothelial-to-mesenchymal-transition, but whether cardiac fibroblasts can adopt an endothelial cell fate and directly contribute to neovascularization after cardiac injury is not known. Here, using genetic fate map techniques, we demonstrate that cardiac fibroblasts rapidly adopt an endothelial cell like phenotype after acute ischemic cardiac injury. Fibroblast derived endothelial cells exhibit anatomical and functional characteristics of native endothelial cells. We show that the transcription factor p53 regulates such a switch in cardiac fibroblast fate. Loss of p53 in cardiac fibroblasts severely decreases the formation of fibroblast derived endothelial cells, reduces post infarct vascular density and worsens cardiac function. Conversely, stimulation of the p53 pathway in cardiac fibroblasts augments mesenchymal to endothelial transition, enhances vascularity and improves cardiac function. These observations demonstrate that mesenchymal-to-endothelial-transition contributes to neovascularization of the injured heart and represents a potential therapeutic target for enhancing cardiac repair. PMID:25317562

  1. Endothelial progenitor cells: a new player in lupus?

    PubMed

    Haque, Sahena; Alexander, M Yvonne; Bruce, Ian N

    2012-01-01

    Patients with systemic lupus erythematosus (SLE) have a greatly increased risk of cardiovascular disease. There is growing interest in the link between vascular damage and lupus-specific inflammatory factors. Impaired endothelial repair could account for the endothelial dysfunction in this patient group. This review describes the contribution that endothelial progenitor cells could play in the pathogenesis of premature vascular damage in this disease. The methods of isolation, detection, and characterization of endothelial progenitor cells, together with their potential role in repair of the endothelium and as a therapeutic target in SLE, are discussed. PMID:22356717

  2. Endothelial Lessons.

    PubMed

    Vanhoutte, Paul M

    2016-01-01

    This essay focuses on nine important lessons learned during more than thirty years of endothelial research. They include: the danger of hiding behind a word, the confusion generated by abbreviations, the need to define the physiological role of the response studied, the local role of endothelium- dependent responses, the strength of pharmacological analyses, endothelial dysfunction as consequence and cause of disease, the importance of rigorous protocols, the primacy of in vivo studies and the importance of serendipity. PMID:26638800

  3. The relationship between oxidised LDL, endothelial progenitor cells and coronary endothelial function in patients with CHD

    PubMed Central

    Watt, Jonathan; Kennedy, Simon; Ahmed, Nadeem; Hayhurst, James; McClure, John D; Berry, Colin; Wadsworth, Roger M; Oldroyd, Keith G

    2016-01-01

    Objective The balance between coronary endothelial dysfunction and repair is influenced by many protective and deleterious factors circulating in the blood. We studied the relationship between oxidised low-density lipoprotein (oxLDL), circulating endothelial progenitor cells (EPCs) and coronary endothelial function in patients with stable coronary heart disease (CHD). Methods 33 patients with stable CHD were studied. Plasma oxLDL was measured using ELISA, coronary endothelial function was assessed using intracoronary acetylcholine infusion and EPCs were quantified using flow cytometry for CD34+/KDR+ cells. Results Plasma oxLDL correlated positively with the number of EPCs in the blood (r=0.46, p=0.02). There was a positive correlation between the number of circulating EPCs and coronary endothelial function (r=0.42, p=0.04). There was no significant correlation between oxLDL and coronary endothelial function. Conclusions Plasma levels of oxLDL are associated with increased circulating EPCs in the blood of patients with CHD, which may reflect a host-repair response to endothelial injury. Patients with stable CHD had a high prevalence of coronary endothelial dysfunction, which was associated with lower numbers of circulating EPCs, suggesting a mechanistic link between endothelial dysfunction and the pathogenesis of atherosclerosis. PMID:26848395

  4. ENDOTHELIAL CELLS IN ALLOGRAFT REJECTION

    PubMed Central

    Al-Lamki, Rafia S.; Bradley, John R.; Pober, Jordan S.

    2008-01-01

    In organ transplantation, blood borne cells and macromolecules (e.g. antibodies) of the host immune system are brought into direct contact with the endothelial cell (EC) lining of graft vessels. In this location, graft ECs play several roles in allograft rejection, including the initiation of rejection responses by presentation of alloantigen to circulating T cells; the development of inflammation and thrombosis; and as targets of injury and agents of repair. PMID:19034000

  5. Mitochondrial and nuclear DNA-repair capacity of various brain regions in mouse is altered in an age-dependent manner.

    PubMed

    Imam, Syed Z; Karahalil, Bensu; Hogue, Barbara A; Souza-Pinto, Nadja C; Bohr, Vilhelm A

    2006-08-01

    Aging is associated with increased susceptibility to neuronal loss and disruption of cerebral function either as a component of senescence, or as a consequence of neurodegenerative disease or stroke. Here we report differential changes in the repair of oxidative DNA damage in various brain regions during aging. We evaluated mitochondrial and nuclear incision activities of oxoguanine DNA glycosylase (OGG1), uracil DNA glycosylase (UDG) and the endonuclease III homologue (NTH1) in the caudate nucleus (CN), frontal cortex (FC), hippocampus (Hip), cerebellum (CE) and brain stem (BS) of 6- and 18-month-old male C57Bl/6 mice. We observed a significant age-dependent decrease in incision activities of all three glycosylases in the mitochondria of all brain regions, whereas variable patterns of changes were seen in nuclei. No age- or region-specific changes were observed in the mitochondrial repair synthesis incorporation of uracil-initiated base-excision repair (BER). We did not observe any age or region dependent differences in levels of BER proteins among the five brain regions. In summary, our data suggest that a decreased efficiency of mitochondrial BER-glycosylases and increased oxidative damage to mitochondrial DNA might contribute to the normal aging process. These data provide a novel characterization of oxidative DNA damage processing in different brain regions implicated in various neurodegenerative disorders, and suggest that this process is regulated in an age-dependent manner. Manipulation of DNA repair mechanisms may provide a strategy to prevent neuronal loss during age-dependent neurodegenerative disorders. PMID:16005114

  6. Inflammasome activation of IL-18 results in endothelial progenitor cell dysfunction in systemic lupus erythematosus.

    PubMed

    Kahlenberg, J Michelle; Thacker, Seth G; Berthier, Celine C; Cohen, Clemens D; Kretzler, Matthias; Kaplan, Mariana J

    2011-12-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous manifestations including severe organ damage and vascular dysfunction leading to premature atherosclerosis. IFN-α has been proposed to have an important role in the development of lupus and lupus-related cardiovascular disease, partly by repression of IL-1 pathways leading to impairments in vascular repair induced by endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs). Counterintuitively, SLE patients also display transcriptional upregulation of the IL-1β/IL-18 processing machinery, the inflammasome. To understand this dichotomy and its impact on SLE-related cardiovascular disease, we examined cultures of human and murine control or lupus EPC/CACs to determine the role of the inflammasome in endothelial differentiation. We show that caspase-1 inhibition improves dysfunctional SLE EPC/CAC differentiation into mature endothelial cells and blocks IFN-α-mediated repression of this differentiation, implicating inflammasome activation as a crucial downstream pathway leading to aberrant vasculogenesis. Furthermore, serum IL-18 levels are elevated in SLE and correlate with EPC/CAC dysfunction. Exogenous IL-18 inhibits endothelial differentiation in control EPC/CACs and neutralization of IL-18 in SLE EPC/CAC cultures restores their capacity to differentiate into mature endothelial cells, supporting a deleterious effect of IL-18 on vascular repair in vivo. Upregulation of the inflammasome machinery was operational in vivo, as evidenced by gene array analysis of lupus nephritis biopsies. Thus, the effects of IFN-α are complex and contribute to an elevated risk of cardiovascular disease by suppression of IL-1β pathways and by upregulation of the inflammasome machinery and potentiation of IL-18 activation.

  7. Reduced Ang2 expression in aging endothelial cells.

    PubMed

    Hohensinner, P J; Ebenbauer, B; Kaun, C; Maurer, G; Huber, K; Wojta, J

    2016-06-01

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. PMID:27137842

  8. Retinal Endothelial Cell Apoptosis Stimulates Recruitment of Endothelial Progenitor Cells

    PubMed Central

    Bhatwadekar, Ashay D.; Glenn, Josephine V.; Curtis, Tim M.; Grant, Maria B.; Stitt, Alan W.; Gardiner, Tom A.

    2013-01-01

    Purpose Bone marrow–derived endothelial progenitor cells (EPCs) contribute to vascular repair although it is uncertain how local endothelial cell apoptosis influences their reparative function. This study was conducted to determine how the presence of apoptotic bodies at sites of endothelial damage may influence participation of EPCs in retinal microvascular repair. Methods Microlesions of apoptotic cell death were created in monolayers of retinal microvascular endothelial cells (RMECs) by using the photodynamic drug verteporfin. The adhesion of early-EPCs to these lesions was studied before detachment of the apoptotic cells or after their removal from the wound site. Apoptotic bodies were fed to normal RMECs and mRNA levels for adhesion molecules were analyzed. Results Endothelial lesions where apoptotic bodies were left attached at the wound site showed a fivefold enhancement in EPC recruitment (P < 0.05) compared with lesions where the apoptotic cells had been removed. In intact RMEC monolayers exposed to apoptotic bodies, expression of ICAM, VCAM, and E-selectin was upregulated by 5- to 15-fold (P < 0.05– 0.001). EPCs showed a characteristic chemotactic response (P < 0.05) to conditioned medium obtained from apoptotic bodies, whereas analysis of the medium showed significantly increased levels of VEGF, IL-8, IL-6, and TNF-α when compared to control medium; SDF-1 remained unchanged. Conclusions The data indicate that apoptotic bodies derived from retinal capillary endothelium mediate release of proangiogenic cytokines and chemokines and induce adhesion molecule expression in a manner that facilitates EPC recruitment. PMID:19474402

  9. Increased circulating inflammatory endothelial cells in blacks with essential hypertension.

    PubMed

    Eirin, Alfonso; Zhu, Xiang-Yang; Woollard, John R; Herrmann, Sandra M; Gloviczki, Monika L; Saad, Ahmed; Juncos, Luis A; Calhoun, David A; Rule, Andrew D; Lerman, Amir; Textor, Stephen C; Lerman, Lilach O

    2013-09-01

    Morbidity and mortality attributable to hypertension are higher in black essential hypertensive (EH) compared with white EH patients, possibly related to differential effects on vascular injury and repair. Although circulating endothelial progenitor cells (EPCs) preserve endothelial integrity, inflammatory endothelial cells (IECs) detach from sites of injury and represent markers of vascular damage. We hypothesized that blood levels of IECs and inflammatory markers would be higher in black EH compared with white EH patients. Inferior vena cava and renal vein levels of CD34+/KDR+ (EPC) and VAP-1+ (IEC) cells were measured by fluorescence-activated cell sorting in white EH and black EH patients under fixed sodium intake and blockade of the renin-angiotensin system, and compared with systemic levels in normotensive control subjects (n=19 each). Renal vein and inferior vena cava levels of inflammatory cytokines and EPC homing factors were measured by Luminex. Blood pressure, serum creatinine, lipids, and antihypertensive medications did not differ between white and black EH patients, and EPC levels were decreased in both. Circulating IEC levels were elevated in black EH patients, and inversely correlated with EPC levels (R(2)=0.58; P=0.0001). Systemic levels of inflammatory cytokines and EPC homing factors were higher in black EH compared with white EH patients, and correlated directly with IECs. Renal vein inflammatory cytokines, EPCs, and IECs did not differ from their circulating levels. Most IECs expressed endothelial markers, fewer expressed progenitor cell markers, but none showed lymphocyte or phagocytic cell markers. Thus, increased release of cytokines and IECs in black EH patients may impair EPC reparative capacity and aggravate vascular damage, and accelerate hypertension-related complications.

  10. Long duration exposure to cadmium leads to increased cell survival, decreased DNA repair capacity, and genomic instability in mouse testicular Leydig cells.

    PubMed

    Singh, Kamaleshwar P; Kumari, Ragini; Pevey, Christina; Jackson, Desiree; DuMond, James W

    2009-06-28

    Epidemiological and experimental studies have shown that cadmium is carcinogenic to human and experimental animals, however, the mechanism of cadmium-induced carcinogenesis is not clear. The aberrant expression of cell cycle and DNA repair genes resulting in increased cell proliferation and genomic instability are the characteristic features of cancer cells. The purpose of this study was to determine if exposure to cadmium can perturb cell proliferation/survival and causes genomic instability in TM3 cells, a mouse testicular Leydig cell line. The results of this study revealed that short-duration exposure to lower doses of cadmium significantly increase the growth of TM3 cells, whereas, higher doses are toxic and cause cell death. The long duration exposure to higher doses of cadmium, however, results in increased cell survival and acquisition of apoptotic resistance. Gene expression analysis by real-time PCR revealed increased expression of the anti-apoptotic gene Bcl-2, whereas decreased expression of pro-apoptotic gene Bax. Decreased expression of genes for maintenance of DNA methylation, DNMT1, and DNA repair, OGG1 and MYH, was also observed in cells exposed to cadmium for 24h. The random amplified polymorphic DNA (RAPD) assay revealed genomic instability in cells with chronic exposure to cadmium. The findings of this study indicate that mouse testicular Leydig cells adapt to chronic cadmium exposure by increasing cell survival through increased expression of Bcl-2, and decreased expression of Bax. The increased proliferation of cells with genomic instability may result in malignant transformation, and therefore, could be a viable mechanism for cadmium-induced cancers. PMID:19232459

  11. Clubfoot repair

    MedlinePlus

    ... release; Talipes equinovarus - repair; Tibialis anterior tendon transfer Images Clubfoot repair - series References Kelly DM. Congenital Anomalies ... provided herein should not be used during any medical emergency or for the diagnosis or treatment of ...

  12. Tendon repair

    MedlinePlus

    Repair of tendon ... Tendon repair can be performed using: Local anesthesia (the immediate area of the surgery is pain-free) ... a cut on the skin over the injured tendon. The damaged or torn ends of the tendon ...

  13. Circulating and tissue resident endothelial progenitor cells.

    PubMed

    Basile, David P; Yoder, Mervin C

    2014-01-01

    Progenitor cells for the endothelial lineage have been widely investigated for more than a decade, but continue to be controversial since no unique identifying marker has yet been identified. This review will begin with a discussion of the basic tenets originally proposed for proof that a cell displays properties of an endothelial progenitor cell. We then provide an overview of the methods for putative endothelial progenitor cell derivation, expansion, and enumeration. This discussion includes consideration of cells that are present in the circulation as well as cells resident in the vascular endothelial intima. Finally, we provide some suggested changes in nomenclature that would greatly clarify and demystify the cellular elements involved in vascular repair.

  14. Cytotoxic, mutagenic, and carcinogenic effects of energy-related agents in diploid human cells which differ in DNA repair capacity. Progress report, 1980-1983

    SciTech Connect

    McCormick, J.J.; Maher, V.M.

    1983-01-01

    The mechanisms of action of a series of energy-related chemical carcinogens to bring about cell killing, the induction of mutations, and the transformation of diploid human fibroblasts in culture were examined. Some of these studies have employed direct-acting compounds (reactive derivatives or metabolites of parent compounds) such as (+-)-7..beta..,8..cap alpha..-dihydroxy9..cap alpha.., 10..cap alpha..-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (anti BPDE), the 4,5-epoxide of benzo(a)pyrene(B(a)P 4,5-oxide), and aflatoxin B/sub 1/-dichloride (AFB/sub 1/-Cl/sub 2/). In other studies, human epithelial cell lines have served as source of the various metabolizing enzymes needed to convert parent compounds into reactive intermediates. We screened a series of 15 epithelial cell lines with unlimited lifespan (derived from various human carcinomas) for the ability to activate representative polycyclic aromatic hydrocarbons, aromatic amides, nitrogen heterocyclics, nitro samines, and/or aflatoxins. Candidate metabolizing cells were then combined with diploid human fibroblasts as target cells in a cell-mediated assay of the mutagenic and/or cytotoxic effect of particular energy-related chemical carcinogens, such as B(a)P, benzofluoranthenes, and dibenzo(c,g)carbazole. The number and kind of major DNA adducts formed in human cells by these chemicals were determined. Comparative studies of anti BPDE and B(a)P 4,5-oxide showed that in diploid human fibroblasts, both normal and DNA repair deficient, these agents do not differ significantly in mutagenic efficiency (per mean lethal event) or mutagenic effectiveness (per DNA adduct). In diploid Chinese hamster embryo fibroblasts anti BPDE had approx. 4-fold higher mutagenic efficiency than B(a)P 4,5-oxide in the latter cells. FA cells were significantly more sensitive than normal to killing by anti BPDE.

  15. SNEV overexpression extends the life span of human endothelial cells

    SciTech Connect

    Voglauer, Regina; Chang, Martina Wei-Fen; Dampier, Brigitta; Wieser, Matthias; Baumann, Kristin; Sterovsky, Thomas; Schreiber, Martin; Katinger, Hermann; Grillari, Johannes . E-mail: j.grillari@iam.boku.ac.at

    2006-04-01

    In a recent screening for genes downregulated in replicatively senescent human umbilical vein endothelial cells (HUVECs), we have isolated the novel protein SNEV. Since then SNEV has proven as a multifaceted protein playing a role in pre-mRNA splicing, DNA repair, and the ubiquitin/proteosome system. Here, we report that SNEV mRNA decreases in various cell types during replicative senescence, and that it is increased in various immortalized cell lines, as well as in breast tumors, where SNEV transcript levels also correlate with the survival of breast cancer patients. Since these mRNA profiles suggested a role of SNEV in the regulation of cell proliferation, the effect of its overexpression was tested. Thereby, a significant extension of the cellular life span was observed, which was not caused by altered telomerase activity or telomere dynamics but rather by enhanced stress resistance. When SNEV overexpressing cells were treated with bleomycin or bleomycin combined with BSO, inducing DNA damage as well as reactive oxygen species, a significantly lower fraction of apoptotic cells was found in comparison to vector control cells. These data suggest that high levels of SNEV might extend the cellular life span by increasing the resistance to stress or by improving the DNA repair capacity of the cells.

  16. Endothelial dysfunction: a comprehensive appraisal

    PubMed Central

    Esper, Ricardo J; Nordaby, Roberto A; Vilariño, Jorge O; Paragano, Antonio; Cacharrón, José L; Machado, Rogelio A

    2006-01-01

    The endothelium is a thin monocelular layer that covers all the inner surface of the blood vessels, separating the circulating blood from the tissues. It is not an inactive organ, quite the opposite. It works as a receptor-efector organ and responds to each physical or chemical stimulus with the release of the correct substance with which it may maintain vasomotor balance and vascular-tissue homeostasis. It has the property of producing, independently, both agonistic and antagonistic substances that help to keep homeostasis and its function is not only autocrine, but also paracrine and endocrine. In this way it modulates the vascular smooth muscle cells producing relaxation or contraction, and therefore vasodilatation or vasoconstriction. The endothelium regulating homeostasis by controlling the production of prothrombotic and antithrombotic components, and fibrynolitics and antifibrynolitics. Also intervenes in cell proliferation and migration, in leukocyte adhesion and activation and in immunological and inflammatory processes. Cardiovascular risk factors cause oxidative stress that alters the endothelial cells capacity and leads to the so called endothelial "dysfunction" reducing its capacity to maintain homeostasis and leads to the development of pathological inflammatory processes and vascular disease. There are different techniques to evaluate the endothelium functional capacity, that depend on the amount of NO produced and the vasodilatation effect. The percentage of vasodilatation with respect to the basal value represents the endothelial functional capacity. Taking into account that shear stress is one of the most important stimulants for the synthesis and release of NO, the non-invasive technique most often used is the transient flow-modulate "endothelium-dependent" post-ischemic vasodilatation, performed on conductance arteries such as the brachial, radial or femoral arteries. This vasodilatation is compared with the vasodilatation produced by drugs that

  17. Vascular effects of multiwalled carbon nanotubes in dyslipidemic ApoE-/- mice and cultured endothelial cells.

    PubMed

    Cao, Yi; Jacobsen, Nicklas Raun; Danielsen, Pernille Høgh; Lenz, Anke G; Stoeger, Tobias; Loft, Steffen; Wallin, Håkan; Roursgaard, Martin; Mikkelsen, Lone; Møller, Peter

    2014-03-01

    Accumulating evidences indicate that pulmonary exposure to carbon nanotubes (CNTs) is associated with increased risk of lung diseases, whereas the effect on the vascular system is less studied. We investigated vascular effects of 2 types of multiwalled CNTs (MWCNTs) in apolipoprotein E(-/-) mice, wild-type mice, and cultured cells. The ApoE(-/-) mice had accelerated plaque progression in aorta after 5 intracheal instillations of MWCNT (25.6 μg/mouse weekly for 5 weeks). The exposure was associated with pulmonary inflammation, lipid peroxidation, and increased expression of inflammatory, oxidative stress, DNA repair, and vascular activation response genes. The level of oxidatively damaged DNA in lung tissue was unaltered, probably due to increased DNA repair capacities. Despite upregulation of inflammatory genes in the liver, effects on systemic cytokines and lipid peroxidation were minimal. The exposure to MWCNTs in cultured human endothelial cells increased the expression of cell adhesion molecules (ICAM1 and VCAM1). In cocultures, there was increased adhesion of monocytes to endothelial cells after exposure to MWCNT. The exposure to both types of MWCNT was also associated with increased lipid accumulation in monocytic-derived foam cells, which was dependent on concomitant oxidative stress because the antioxidant N-acetylcysteine inhibited the lipid accumulation. Collectively, our results indicate that exposure to MWCNT is associated with accelerated progression of atherosclerosis, which could be related to both increased adherence of monocytes onto the endothelium and oxidative stress-mediated transformation of monocytes to foam cells.

  18. DNA repair in cultured keratinocytes

    SciTech Connect

    Liu, S.C.; Parsons, S.; Hanawalt, P.C.

    1983-07-01

    Most of our understanding of DNA repair mechanisms in human cells has come from the study of these processes in cultured fibroblasts. The unique properties of keratinocytes and their pattern of terminal differentiation led us to a comparative examination of their DNA repair properties. The relative repair capabilities of the basal cells and the differentiated epidermal keratinocytes as well as possible correlations of DNA repair capacity with respect to age of the donor have been examined. In addition, since portions of human skin are chronically exposed to sunlight, the repair response to ultraviolet (UV) irradiation (254 nm) when the cells are conditioned by chronic low-level UV irradiation has been assessed. The comparative studies of DNA repair in keratinocytes from infant and aged donors have revealed no significant age-related differences for repair of UV-induced damage to DNA. Sublethal UV conditioning of cells from infant skin had no appreciable effect on either the repair or normal replication response to higher, challenge doses of UVL. However, such conditioning resulted in attenuated repair in keratinocytes from adult skin after UV doses above 25 J/m2. In addition, a surprising enhancement in replication was seen in conditioned cells from adult following challenge UV doses.

  19. DNA repair in cultured keratinocytes.

    PubMed

    Liu, S C; Parsons, S; Hanawalt, P C

    1983-07-01

    Most of our understanding of DNA repair mechanisms in human cells has come from the study of these processes in cultured fibroblasts. The unique properties of keratinocytes and their pattern of terminal differentiation led us to a comparative examination of their DNA repair properties. We have examined the relative repair capabilities of the basal cells and the differentiated epidermal keratinocytes as well as possible correlations of DNA repair capacity with respect to age of the donor. In addition, since portions of human skin are chronically exposed to sunlight, we have assessed the repair response to ultraviolet (UV) irradiation (254 nm) when the cells are conditioned by chronic low-level UV irradiation. The methods of Liu and Karasek were used to grow pure keratinocytes on collagen gels following their isolation from abdominal skin of newborns and adults at autopsy. Density labeling with 5-bromodeoxyuridine was used to resolve repair replication from the semiconservative mode. We found similar repair characteristics in human epidermal keratinocytes to those previously reported for cultured fibroblasts. However, the DNA repair response in basal cells was much greater than that in differentiated cells from the same skin preparation. Our comparative studies of DNA repair in keratinocytes from infant and aged donors have revealed no significant age-related differences for repair of UV-induced damage to DNA. Sublethal UV conditioning of cells from infant skin had no appreciable effect on either the repair or normal replication response to higher, challenge doses of UVL. However, such conditioning resulted in attenuated repair in keratinocytes from adult skin after UV doses above 25 J/m2. In addition, a surprising enhancement in replication was seen in conditioned cells from adult following challenge UV doses.

  20. Endothelial cells enhance migration of meniscus cells

    PubMed Central

    Yuan, Xiaoning; Eng, George M.; Arkonac, Derya E.; Chao, Pen-hsiu Grace; Vunjak-Novakovic, Gordana

    2014-01-01

    Objective To study the interactions between vascular endothelial cells and meniscal fibrochondrocytes from the inner avascular and outer vascular regions of the meniscus, and identify angiogenic factors that enhance cell migration and integrative repair. Methods Bovine meniscal fibrochondrocytes (bMFCs) from the inner and outer regions of meniscus were cultured for seven days with and without human umbilical vein endothelial cells (HUVECs) in a micropatterned three-dimensional hydrogel system for cell migration. Angiogenic factors secreted by HUVECs were probed for their role in paracrine mechanisms governing bMFC migration, and applied to a full-thickness defect model of meniscal repair in explants from the inner and outer regions over four weeks. Results Endothelial cells enhanced migration of inner and outer bMFCs in the micropatterned system via endothelin-1 (ET-1) signaling. Supplementation of ET-1 significantly enhanced integration strength of full-thickness defects in inner and outer explants, and cell migration at the macro-scale, compared to controls without ET-1 treatment. Conclusion We report for the first time that bMFCs from both the avascular and vascular regions respond to the presence of endothelial cells with increased migration. Paracrine signaling by endothelial cells regulates the bMFCs differentially by region, but we identify ET-1 as an angiogenic factor that stimulates migration of inner and outer cells at the micro-scale, and integrative repair of inner and outer explants at the macro-scale. These findings reveal the regional interactions between vasculature and MFCs, and suggest ET-1 as a potential new treatment modality for avascular meniscal injuries, in order to prevent the development of osteoarthritis. PMID:25307081

  1. The immune system and cardiac repair

    PubMed Central

    Frangogiannis, Nikolaos G.

    2008-01-01

    Myocardial infarction is the most common cause of cardiac injury and results in acute loss of a large number of myocardial cells. Because the heart has negligible regenerative capacity, cardiomyocyte death triggers a reparative response that ultimately results in formation of a scar and is associated with dilative remodeling of the ventricle. Cardiac injury activates innate immune mechanisms initiating an inflammatory reaction. Toll Like Receptor-mediated pathways, the complement cascade and reactive oxygen generation induce Nuclear Factor (NF)-κB activation and upregulate chemokine and cytokine synthesis in the infarcted heart. Chemokines stimulate the chemotactic recruitment of inflammatory leukocytes into the infarct, while cytokines promote adhesive interactions between leukocytes and endothelial cells, resulting in transmigration of inflammatory cells into the site of injury. Monocyte subsets play distinct roles in phagocytosis of dead cardiomyocytes and in granulation tissue formation through the release of growth factors. Clearance of dead cells and matrix debris may be essential for resolution of inflammation and transition into the reparative phase. Transforming Growth Factor (TGF)-β plays a crucial role in cardiac repair by suppressing inflammation while promoting myofibroblast phenotypic modulation and extracellular matrix deposition. Myofibroblast proliferation and angiogenesis result in formation of highly vascularized granulation tissue. As the healing infarct matures, fibroblasts become apoptotic and a collagen-based matrix is formed, while many infarct neovessels acquire a muscular coat and uncoated vessels regress. Timely resolution of the inflammatory infiltrate and spatial containment of the inflammatory and reparative response into the infarcted area are essential for optimal infarct healing. Targeting inflammatory pathways following infarction may reduce cardiomyocyte injury and attenuate adverse remodeling. In addition, understanding the

  2. Craniosynostosis repair

    MedlinePlus

    ... will be asleep and will not feel pain. Traditional surgery is called open repair. It includes these ... helps keep the swelling down. Talking, singing, playing music, and telling stories may help soothe your child. ...

  3. Mitochondria, endothelial cell function, and vascular diseases

    PubMed Central

    Tang, Xiaoqiang; Luo, Yu-Xuan; Chen, Hou-Zao; Liu, De-Pei

    2014-01-01

    Mitochondria are perhaps the most sophisticated and dynamic responsive sensing systems in eukaryotic cells. The role of mitochondria goes beyond their capacity to create molecular fuel and includes the generation of reactive oxygen species, the regulation of calcium, and the activation of cell death. In endothelial cells, mitochondria have a profound impact on cellular function under both healthy and diseased conditions. In this review, we summarize the basic functions of mitochondria in endothelial cells and discuss the roles of mitochondria in endothelial dysfunction and vascular diseases, including atherosclerosis, diabetic vascular dysfunction, pulmonary artery hypertension, and hypertension. Finally, the potential therapeutic strategies to improve mitochondrial function in endothelial cells and vascular diseases are also discussed, with a focus on mitochondrial-targeted antioxidants and calorie restriction. PMID:24834056

  4. Pectus excavatum repair

    MedlinePlus

    Funnel chest repair; Chest deformity repair; Sunken chest repair; Cobbler's chest repair; Nuss repair; Ravitch repair ... There are two types of surgery to repair this condition -- open surgery ... surgery is done while the child is in a deep sleep and pain- ...

  5. Femoral hernia repair

    MedlinePlus

    Femorocele repair; Herniorrhaphy; Hernioplasty - femoral ... During surgery to repair the hernia, the bulging tissue is pushed back in. The weakened area is sewn closed or strengthened. This repair ...

  6. Undescended testicle repair

    MedlinePlus

    Orchidopexy; Inguinal orchidopexy; Orchiopexy; Repair of undescended testicle; Cryptorchidism repair ... first year of life without treatment. Undescended testicle repair surgery is recommended for patients whose testicles do ...

  7. [Vascular endothelial Barrier Function].

    PubMed

    Ivanov, A N; Puchinyan, D M; Norkin, I A

    2015-01-01

    Endothelium is an important regulator of selective permeability of the vascular wall for different molecules and cells. This review summarizes current data on endothelial barrier function. Endothelial glycocalyx structure, its function and role in the molecular transport and leukocytes migration across the endothelial barrier are discussed. The mechanisms of transcellular transport of macromolecules and cell migration through endothelial cells are reviewed. Special section of this article addresses the structure and function of tight and adherens endothelial junction, as well as their importance for the regulation of paracellular transport across the endothelial barrier. Particular attention is paid to the signaling mechanism of endothelial barrier function regulation and the factors that influence on the vascular permeability.

  8. Human Endothelial Cells: Use of Heparin in Cloning and Long-Term Serial Cultivation

    NASA Astrophysics Data System (ADS)

    Thornton, Susan C.; Mueller, Stephen N.; Levine, Elliot M.

    1983-11-01

    Endothelial cells from human blood vessels were cultured in vitro, with doubling times of 17 to 21 hours for 42 to 79 population doublings. Cloned human endothelial cell strains were established for the first time and had similar proliferative capacities. This vigorous cell growth was achieved by addition of heparin to culture medium containing reduced concentrations of endothelial cell growth factor. The routine cloning and long-term culture of human endothelial cells will facilitate studying the human endothelium in vitro.

  9. Wnt Signaling During Fracture Repair

    PubMed Central

    Secreto, Frank J.; Hoeppner, Luke H.; Westendorf, Jennifer J.

    2010-01-01

    Bone is one of the few tissues in the body with the capacity to regenerate and repair itself. In most cases, fractures are completely repaired in a relatively short period of time; however, in a small percentage of cases, healing never occurs and non-union is the result. Fracture repair and bone regeneration require the localized re-activation of signaling cascades that are crucial for skeletal development. The Wnt/β-catenin signaling pathway is one such developmental pathway whose role in bone formation and regeneration has been recently appreciated. During the last decade, much has learned about how Wnt pathways regulate bone mass. Small molecules and biologics aimed at this pathway are now being tested as potential new anabolic agents. Here we review recent data demonstrating that Wnt pathways are active during fracture repair and that increasing the activities of Wnt pathway components accelerates bone regeneration. PMID:19631031

  10. Intestinal obstruction repair

    MedlinePlus

    Repair of volvulus; Intestinal volvulus - repair; Bowel obstruction - repair ... Intestinal obstruction repair is done while you are under general anesthesia . This means you are asleep and DO NOT feel pain. ...

  11. Motorcycle Repair.

    ERIC Educational Resources Information Center

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  12. Outboard Repair.

    ERIC Educational Resources Information Center

    Hardway, Jack

    This consortium-developed instructor's manual for small engine repair (with focus on outboard motors) consists of the following nine instructional units: electrical remote control assembly, mechanical remote control assembly, tilt assemblies, exhaust housing, propeller and trim tabs, cooling system, mechanical gearcase, electrical gearcase, and…

  13. Snowmobile Repair.

    ERIC Educational Resources Information Center

    Helbling, Wayne

    This guide is designed to provide and/or improve instruction for occupational training in the area of snowmobile repair, and includes eight areas. Each area consists of one or more units of instruction, with each instructional unit including some or all of the following basic components: Performance objectives, suggested activities for teacher and…

  14. Turbine repair process, repaired coating, and repaired turbine component

    SciTech Connect

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  15. 33 CFR 158.240 - Ship repair yards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  16. 33 CFR 158.240 - Ship repair yards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  17. 33 CFR 158.240 - Ship repair yards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  18. 33 CFR 158.240 - Ship repair yards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  19. 33 CFR 158.240 - Ship repair yards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ship repair yards. 158.240... Facilities: Oily Mixtures § 158.240 Ship repair yards. The reception facility that services oceangoing ships using a ship repair yard must have a capacity for receiving— (a) An amount of ballast from bunker...

  20. [Endothelial cell adhesion molecules].

    PubMed

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  1. Radiosensitisation by pharmacological ascorbate in glioblastoma multiforme cells, human glial cells, and HUVECs depends on their antioxidant and DNA repair capabilities and is not cancer specific.

    PubMed

    Castro, M Leticia; McConnell, Melanie J; Herst, Patries M

    2014-09-01

    We previously showed that 5 mM ascorbate radiosensitized early passage radioresistant glioblastoma multiforme (GBM) cells derived from one patient tumor. Here we investigate the sensitivity of a panel of cell lines to 5 mM ascorbate and 6 Gy ionizing radiation, made up of three primary human GBM cells, three GBM cell lines, a human glial cell line, and primary human vascular endothelial cells. The response of different cells lines to ascorbate and/or radiation was determined by measuring viability, colony-forming ability, generation and repair of double-stranded DNA breaks (DSBs), cell cycle progression, antioxidant capacity and generation of reactive oxygen species. Individually, radiation and ascorbate both decreased viability and clonogenicity by inducing DNA damage, but had differential effects on cell cycle progression. Radiation led to G2/M arrest in most cells whereas ascorbate caused accumulation in S phase, which was moderately associated with poor DSB repair. While high dose ascorbate radiosensitized all cell lines in clonogenic assays, the sensitivity to radiation, high dose ascorbate, and combined treatment varied between cell lines. Normal glial cells were similar to GBM cells with respect to free radical scavenging potential and effect of treatment on DNA damage and repair, viability, and clonogenicity. Both GBM cells and normal cells coped equally poorly with oxidative stress caused by radiation and/or high dose ascorbate, dependent primarily on their antioxidant and DSB repair capacity.

  2. Immunomodulation in stem cell differentiation into neurons and brain repair.

    PubMed

    Ulrich, Henning; do Nascimento, Isis Cristina; Bocsi, Jozsef; Tárnok, Attila

    2015-06-01

    Immunomodulators regulate stem cell activity at all stages of development as well as during adulthood. Embryonic stem cell (ESC) proliferation as well as neurogenic processes during embryonic development are controlled by factors of the immune system. We review here immunophenotypic expression patterns of  different stem cell types, including ESC, neural (NSC) and tissue-specific mesenchymal stem cells (MSC), and focus on immunodulatory properties of these cells. Immune and inflammatory responses, involving actions of cytokines as well as toll-like receptor (TLR) signaling are known to affect the differentiation capacity of NSC and MSC. Secretion of pro- and anti-inflammatory messengers by MSC have been observed as the consequence of TLR and cytokine activation and promotion of differentiation into specified phenotypes. As result of augmented differentiation capacity, stem cells secrete angiogenic factors including vascular endothelial growth factor, resulting in multifactorial actions in tissue repair. Immunoregulatory properties of tissue specific adult stem cells are put into the context of possible clinical applications.

  3. Assessment of Endothelial Dysfunction in Childhood Obesity and Clinical Use

    PubMed Central

    Hoymans, Vicky Y.; Van Craenenbroeck, Amaryllis H.; Vissers, Dirk K.; Vrints, Christiaan J.; Conraads, Viviane M.

    2013-01-01

    The association of obesity with noncommunicable diseases, such as cardiovascular complications and diabetes, is considered a major threat to the management of health care worldwide. Epidemiological findings show that childhood obesity is rapidly rising in Western society, as well as in developing countries. This pandemic is not without consequences and can affect the risk of future cardiovascular disease in these children. Childhood obesity is associated with endothelial dysfunction, the first yet still reversible step towards atherosclerosis. Advanced research techniques have added further insight on how childhood obesity and associated comorbidities lead to endothelial dysfunction. Techniques used to measure endothelial function were further brought to perfection, and novel biomarkers, including endothelial progenitor cells, were discovered. The aim of this paper is to provide a critical overview on both in vivo as well as in vitro markers for endothelial integrity. Additionally, an in-depth description of the mechanisms that disrupt the delicate balance between endothelial damage and repair will be given. Finally, the effects of lifestyle interventions and pharmacotherapy on endothelial dysfunction will be reviewed. PMID:23691262

  4. Reduced repair capacity of a DNA clustered damage site comprised of 8-oxo-7,8-dihydro-2'-deoxyguanosine and 2-deoxyribonolactone results in an increased mutagenic potential of these lesions

    DOE PAGES

    Cunniffe, Siobhan; O’Neill, Peter; Greenberg, Marc M.; Lomax, Martine E.

    2014-04-01

    A signature of ionizing radiation is the induction of DNA clustered damaged sites. Non-double strand break (DSB) clustered damage has been shown to compromise the base excision repair pathway, extending the lifetimes of the lesions within the cluster, compared to isolated lesions. This increases the likelihood the lesions persist to replication and thus increasing the mutagenic potential of the lesions within the cluster. Lesions formed by ionizing radiation include 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and 2-deoxyribonolactone (dL). dL poses an additional challenge to the cell as it is not repaired by the short-patch base excision repair pathway. Here we show recalcitrant dL repairmore » is reflected in mutations observed when DNA containing it and a proximal 8-oxodGuo is replicated in Escherichia coli. 8-oxodGuo in close proximity to dL on the opposing DNA strand results in an enhanced frequency of mutation of the lesions within the cluster and a 20 base sequence flanking the clustered damage site in an E. coli based plasmid assay. In vitro repair of a dL lesion is reduced when compared to the repair of an abasic (AP) site and a tetrahydrofuran (THF), and this is due mainly to a reduction in the activity of polymerase β, leading to retarded FEN1 and ligase 1 activities. This study has given insights in to the biological effects of clusters containing dL.« less

  5. Brain aneurysm repair

    MedlinePlus

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  6. Macrophages in Tissue Repair, Regeneration, and Fibrosis.

    PubMed

    Wynn, Thomas A; Vannella, Kevin M

    2016-03-15

    Inflammatory monocytes and tissue-resident macrophages are key regulators of tissue repair, regeneration, and fibrosis. After tissue injury, monocytes and macrophages undergo marked phenotypic and functional changes to play critical roles during the initiation, maintenance, and resolution phases of tissue repair. Disturbances in macrophage function can lead to aberrant repair, such that uncontrolled production of inflammatory mediators and growth factors, deficient generation of anti-inflammatory macrophages, or failed communication between macrophages and epithelial cells, endothelial cells, fibroblasts, and stem or tissue progenitor cells all contribute to a state of persistent injury, and this could lead to the development of pathological fibrosis. In this review, we discuss the mechanisms that instruct macrophages to adopt pro-inflammatory, pro-wound-healing, pro-fibrotic, anti-inflammatory, anti-fibrotic, pro-resolving, and tissue-regenerating phenotypes after injury, and we highlight how some of these mechanisms and macrophage activation states could be exploited therapeutically.

  7. HDL and endothelial protection

    PubMed Central

    Tran-Dinh, A; Diallo, D; Delbosc, S; Varela-Perez, L Maria; Dang, QB; Lapergue, B; Burillo, E; Michel, JB; Levoye, A; Martin-Ventura, JL; Meilhac, O

    2013-01-01

    High-density lipoproteins (HDLs) represent a family of particles characterized by the presence of apolipoprotein A-I (apoA-I) and by their ability to transport cholesterol from peripheral tissues back to the liver. In addition to this function, HDLs display pleiotropic effects including antioxidant, anti-apoptotic, anti-inflammatory, anti-thrombotic or anti-proteolytic properties that account for their protective action on endothelial cells. Vasodilatation via production of nitric oxide is also a hallmark of HDL action on endothelial cells. Endothelial cells express receptors for apoA-I and HDLs that mediate intracellular signalling and potentially participate in the internalization of these particles. In this review, we will detail the different effects of HDLs on the endothelium in normal and pathological conditions with a particular focus on the potential use of HDL therapy to restore endothelial function and integrity. PMID:23488589

  8. Fibronectin Extra Domain A Promotes Liver Sinusoid Repair following Hepatectomy

    PubMed Central

    Sackey-Aboagye, Bridget; Olsen, Abby L.; Mukherjee, Sarmistha M.; Ventriglia, Alexander; Yokosaki, Yasuyuki; Greenbaum, Linda E.; Lee, Gi Yun; Naga, Hani

    2016-01-01

    Liver sinusoidal endothelial cells (LSECs) are the main endothelial cells in the liver and are important for maintaining liver homeostasis as well as responding to injury. LSECs express cellular fibronectin containing the alternatively spliced extra domain A (EIIIA-cFN) and increase expression of this isoform after liver injury, although its function is not well understood. Here, we examined the role of EIIIA-cFN in liver regeneration following partial hepatectomy. We carried out two-thirds partial hepatectomies in mice lacking EIIIA-cFN and in their wild type littermates, studied liver endothelial cell adhesion on decellularized, EIIIA-cFN-containing matrices and investigated the role of cellular fibronectins in liver endothelial cell tubulogenesis. We found that liver weight recovery following hepatectomy was significantly delayed and that sinusoidal repair was impaired in EIIIA-cFN null mice, especially females, as was the lipid accumulation typical of the post-hepatectomy liver. In vitro, we found that liver endothelial cells were more adhesive to cell-deposited matrices containing the EIIIA domain and that cellular fibronectin enhanced tubulogenesis and vascular cord formation. The integrin α9β1, which specifically binds EIIIA-cFN, promoted tubulogenesis and adhesion of liver endothelial cells to EIIIA-cFN. Our findings identify a role for EIIIA-cFN in liver regeneration and tubulogenesis. We suggest that sinusoidal repair is enhanced by increased LSEC adhesion, which is mediated by EIIIA-cFN. PMID:27741254

  9. Protein oxidation, UVA and human DNA repair.

    PubMed

    Karran, Peter; Brem, Reto

    2016-08-01

    Solar UVB is carcinogenic. Nucleotide excision repair (NER) counteracts the carcinogenicity of UVB by excising potentially mutagenic UVB-induced DNA lesions. Despite this capacity for DNA repair, non-melanoma skin cancers and apparently normal sun-exposed skin contain huge numbers of mutations that are mostly attributable to unrepaired UVB-induced DNA lesions. UVA is about 20-times more abundant than UVB in incident sunlight. It does cause some DNA damage but this does not fully account for its biological impact. The effects of solar UVA are mediated by its interactions with cellular photosensitizers that generate reactive oxygen species (ROS) and induce oxidative stress. The proteome is a significant target for damage by UVA-induced ROS. In cultured human cells, UVA-induced oxidation of DNA repair proteins inhibits DNA repair. This article addresses the possible role of oxidative stress and protein oxidation in determining DNA repair efficiency - with particular reference to NER and skin cancer risk.

  10. Endothelial cell tumor growth is Ape/ref-1 dependent.

    PubMed

    Biswas, Ayan; Khanna, Savita; Roy, Sashwati; Pan, Xueliang; Sen, Chandan K; Gordillo, Gayle M

    2015-09-01

    Tumor-forming endothelial cells have highly elevated levels of Nox-4 that release H2O2 into the nucleus, which is generally not compatible with cell survival. We sought to identify compensatory mechanisms that enable tumor-forming endothelial cells to survive and proliferate under these conditions. Ape-1/ref-1 (Apex-1) is a multifunctional protein that promotes DNA binding of redox-sensitive transcription factors, such as AP-1, and repairs oxidative DNA damage. A validated mouse endothelial cell (EOMA) tumor model was used to demonstrate that Nox-4-derived H2O2 causes DNA oxidation that induces Apex-1 expression. Apex-1 functions as a chaperone to keep transcription factors in a reduced state. In EOMA cells Apex-1 enables AP-1 binding to the monocyte chemoattractant protein-1 (mcp-1) promoter and expression of that protein is required for endothelial cell tumor formation. Intraperitoneal injection of the small molecule inhibitor E3330, which specifically targets Apex-1 redox-sensitive functions, resulted in a 50% decrease in tumor volume compared with mice injected with vehicle control (n = 6 per group), indicating that endothelial cell tumor proliferation is dependent on Apex-1 expression. These are the first reported results to establish Nox-4 induction of Apex-1 as a mechanism promoting endothelial cell tumor formation.

  11. Protein kinase D activity controls endothelial nitric oxide synthesis.

    PubMed

    Aicart-Ramos, Clara; Sánchez-Ruiloba, Lucía; Gómez-Parrizas, Mónica; Zaragoza, Carlos; Iglesias, Teresa; Rodríguez-Crespo, Ignacio

    2014-08-01

    Vascular endothelial growth factor (VEGF) regulates key functions of the endothelium, such as angiogenesis or vessel repair in processes involving endothelial nitric oxide synthase (eNOS) activation. One of the effector kinases that become activated in endothelial cells upon VEGF treatment is protein kinase D (PKD). Here, we show that PKD phosphorylates eNOS, leading to its activation and a concomitant increase in NO synthesis. Using mass spectrometry, we show that the purified active kinase specifically phosphorylates recombinant eNOS on Ser1179. Treatment of endothelial cells with VEGF or phorbol 12,13-dibutyrate (PDBu) activates PKD and increases eNOS Ser1179 phosphorylation. In addition, pharmacological inhibition of PKD and gene silencing of both PKD1 and PKD2 abrogate VEGF signaling, resulting in a clear diminished migration of endothelial cells in a wound healing assay. Finally, inhibition of PKD in mice results in an almost complete disappearance of the VEGF-induced vasodilatation, as monitored through determination of the diameter of the carotid artery. Hence, our data indicate that PKD is a new regulatory kinase of eNOS in endothelial cells whose activity orchestrates mammalian vascular tone. PMID:24928905

  12. Coal bunker repairs

    SciTech Connect

    Emmons, M.H.; Hoffman, M.G. )

    1992-01-01

    Detroit Edison's St. Clair Power Plant (STCPP) Units 1 through 4 are 1950's vintage fossil fueled units with an average capacity of 163 megawatt per unit. Each unit had identical 2190 ton bunkers. The Unit No. 1 bunker had been experiencing noticeable exterior deterioration at the lower level internal support system. An internal bunker inspection revealed large deflections in the network of beams supporting the bunker side walls. A complete collapse of the internal support beams was imminent. Failure of these beams would have transferred the coal pressure loads to the bunker skin and external stiffeners which were not capable of sustaining the load and were also showing signs of distress. This paper presents the temporary repair installed immediately after inspection, the redesign of the lower internal support system and construction procedures involved in bringing the bunker back into operating condition.

  13. Book Repair Manual.

    ERIC Educational Resources Information Center

    Milevski, Robert J.

    1995-01-01

    This book repair manual developed for the Illinois Cooperative Conservation Program includes book structure and book problems, book repair procedures for 4 specific problems, a description of adhesive bindings, a glossary, an annotated list of 11 additional readings, book repair supplies and suppliers, and specifications for book repair kits. (LRW)

  14. Endothelial progenitor cells in hematologic malignancies

    PubMed Central

    Saulle, Ernestina; Castelli, Germana; Pelosi, Elvira

    2016-01-01

    Studies carried out in the last years have improved the understanding of the cellular and molecular mechanisms controlling angiogenesis during adult life in normal and pathological conditions. Some of these studies have led to the identification of some progenitor cells that sustain angiogenesis through indirect, paracrine mechanisms (hematopoietic angiogenic cells) and through direct mechanisms, i.e., through their capacity to generate a progeny of phenotypically and functionally competent endothelial cells [endothelial colony forming cells (ECFCs)]. The contribution of these progenitors to angiogenetic processes under physiological and pathological conditions is intensively investigated. Angiogenetic mechanisms are stimulated in various hematological malignancies, including chronic myeloid leukemia (CML), acute myeloid leukemia (AML), myelodysplastic syndromes and multiple myeloma, resulting in an increased angiogenesis that contributes to disease progression. In some of these conditions there is preliminary evidence that some endothelial cells could derive from the malignant clone, thus leading to the speculation that the leukemic cell derives from the malignant transformation of a hemangioblastic progenitor, i.e., of a cell capable of differentiation to the hematopoietic and to the endothelial cell lineages. Our understanding of the mechanisms underlying increased angiogenesis in these malignancies not only contributed to a better knowledge of the mechanisms responsible for tumor progression, but also offered the way for the discovery of new therapeutic targets. PMID:27583252

  15. Endothelial progenitor cells in hematologic malignancies.

    PubMed

    Testa, Ugo; Saulle, Ernestina; Castelli, Germana; Pelosi, Elvira

    2016-01-01

    Studies carried out in the last years have improved the understanding of the cellular and molecular mechanisms controlling angiogenesis during adult life in normal and pathological conditions. Some of these studies have led to the identification of some progenitor cells that sustain angiogenesis through indirect, paracrine mechanisms (hematopoietic angiogenic cells) and through direct mechanisms, i.e., through their capacity to generate a progeny of phenotypically and functionally competent endothelial cells [endothelial colony forming cells (ECFCs)]. The contribution of these progenitors to angiogenetic processes under physiological and pathological conditions is intensively investigated. Angiogenetic mechanisms are stimulated in various hematological malignancies, including chronic myeloid leukemia (CML), acute myeloid leukemia (AML), myelodysplastic syndromes and multiple myeloma, resulting in an increased angiogenesis that contributes to disease progression. In some of these conditions there is preliminary evidence that some endothelial cells could derive from the malignant clone, thus leading to the speculation that the leukemic cell derives from the malignant transformation of a hemangioblastic progenitor, i.e., of a cell capable of differentiation to the hematopoietic and to the endothelial cell lineages. Our understanding of the mechanisms underlying increased angiogenesis in these malignancies not only contributed to a better knowledge of the mechanisms responsible for tumor progression, but also offered the way for the discovery of new therapeutic targets. PMID:27583252

  16. Mechanisms for SU5416 as a radiosensitizer of endothelial cells.

    PubMed

    Kim, Eun Ho; Kim, Mi-Sook; Jeong, Youn Kyoung; Cho, Ilsung; You, Seung Hoon; Cho, Sung Ho; Lee, Hanna; Jung, Won-Gyun; Kim, Hag Dong; Kim, Joon

    2015-10-01

    Endothelial cells (ECs), that comprise the tumor vasculature, are critical targets for anticancer radiotherapy. The aim of this work was to study the mechanism by which SU5416, a known anti-angiogenesis inhibitor, modifies the radiation responses of human vascular ECs. Two human endothelial cell lines (HUVEC and 2H11) were treated with SU5416 alone, radiation alone, or a combination of both. In vitro tests were performed using colony forming assays, FACS analysis, western blotting, immunohistochemistry, migration assay, invasion assays and endothelial tube formation assays. The combination of radiation and SU5416 significantly inhibited cell survival, the repair of radiation-induced DNA damage, and induced apoptosis. It also caused cell cycle arrest, inhibited cell migration and invasion, and suppressed angiogenesis. In this study, our results first provide a scientific rationale to combine SU5416 with radiotherapy to target ECs and suggest its clinical application in combination cancer treatment with radiotherapy.

  17. Evolution of endothelial keratoplasty.

    PubMed

    Price, Francis W; Price, Marianne O

    2013-11-01

    Endothelial keratoplasty has evolved into a popular alternative to penetrating keratoplasty (PK) for the treatment of endothelial dysfunction. Although the earliest iterations were challenging and were not widely adopted, the iteration known as Descemet stripping endothelial keratoplasty (DSEK) has gained widespread acceptance. DSEK combines a simplified technique for stripping dysfunctional endothelium from the host cornea and microkeratome dissection of the donor tissue, a step now commonly completed in advance by eye bank technicians. Studies show that a newer endothelial keratoplasty iteration, known as Descemet membrane endothelial keratoplasty (DMEK), provides an even faster and better visual recovery than DSEK does. In addition, DMEK significantly reduces the risk of immunologic graft rejection episodes compared with that in DSEK or in PK. Although the DMEK donor tissue, consisting of the bare endothelium and Descemet membrane without any stroma, is more challenging to prepare and position in the recipient eye, recent improvements in instrumentation and surgical techniques are increasing the ease and the reliability of the procedure. DSEK successfully mitigates 2 of the main liabilities of PK: ocular surface complications and structural problems (including induced astigmatism and perpetually weak wounds), whereas DMEK further mitigates the 2 principal remaining liabilities of PK: immunologic graft reactions and secondary glaucoma from prolonged topical corticosteroid use.

  18. [Endothelial function and the microcirculation in diabetes mellitus].

    PubMed

    Arosio, E; Minuz, P; Prior, M

    1999-01-01

    The role of endothelial dysfunction in the pathogenesis of diabetic microangiopathy is reviewed. Reversible alterations in microcirculation, consisting of increased capillary pressure, blood flow and endothelial permeability, can be detected at an early stage in diabetes mellitus. Irreversible structural modifications of the vascular wall, such as thickening of the basal membrane due to the extracellular accumulation of proteins, take place at later stages. Atherosclerosis further affects microcirculation in diabetes mellitus by decreasing autoregulatory capacity and blood flow reserve. Endothelial dysfunction has been observed to precede the onset of microvascular lesions, as demonstrated by reduction in the vasodilatory response to vasoactive agents and by alterations in the antithrombotic properties of the endothelium. Experimental data available so far suggest that endothelial dysfunction may be directly related to hyperglycemia. Abnormalities in lipoprotein metabolism, generation of glycation end products, and increased oxidative stress may also be responsible for the endothelial dysfunction in diabetes mellitus. Insulin resistance appears to be related to endothelial dysfunction in non-insulin-dependent diabetes mellitus through a reduction in the biological activity of endothelial-derived nitric oxide.

  19. Vascular endothelial growth factor: an attractive target in the treatment of hypoxic/ischemic brain injury.

    PubMed

    Guo, Hui; Zhou, Hui; Lu, Jie; Qu, Yi; Yu, Dan; Tong, Yu

    2016-01-01

    Cerebral hypoxia or ischemia results in cell death and cerebral edema, as well as other cellular reactions such as angiogenesis and the reestablishment of functional microvasculature to promote recovery from brain injury. Vascular endothelial growth factor is expressed in the central nervous system after hypoxic/ischemic brain injury, and is involved in the process of brain repair via the regulation of angiogenesis, neurogenesis, neurite outgrowth, and cerebral edema, which all require vascular endothelial growth factor signaling. In this review, we focus on the role of the vascular endothelial growth factor signaling pathway in the response to hypoxic/ischemic brain injury, and discuss potential therapeutic interventions. PMID:26981109

  20. Vascular endothelial growth factor: an attractive target in the treatment of hypoxic/ischemic brain injury

    PubMed Central

    Guo, Hui; Zhou, Hui; Lu, Jie; Qu, Yi; Yu, Dan; Tong, Yu

    2016-01-01

    Cerebral hypoxia or ischemia results in cell death and cerebral edema, as well as other cellular reactions such as angiogenesis and the reestablishment of functional microvasculature to promote recovery from brain injury. Vascular endothelial growth factor is expressed in the central nervous system after hypoxic/ischemic brain injury, and is involved in the process of brain repair via the regulation of angiogenesis, neurogenesis, neurite outgrowth, and cerebral edema, which all require vascular endothelial growth factor signaling. In this review, we focus on the role of the vascular endothelial growth factor signaling pathway in the response to hypoxic/ischemic brain injury, and discuss potential therapeutic interventions. PMID:26981109

  1. Regulation of retinal angiogenesis by endothelial nitric oxide synthase signaling pathway.

    PubMed

    Ha, Jung Min; Jin, Seo Yeon; Lee, Hye Sun; Shin, Hwa Kyoung; Lee, Dong Hyung; Song, Sang Heon; Kim, Chi Dae; Bae, Sun Sik

    2016-09-01

    Angiogenesis plays an essential role in embryo development, tissue repair, inflammatory diseases, and tumor growth. In the present study, we showed that endothelial nitric oxide synthase (eNOS) regulates retinal angiogenesis. Mice that lack eNOS showed growth retardation, and retinal vessel development was significantly delayed. In addition, the number of tip cells and filopodia length were significantly reduced in mice lacking eNOS. Retinal endothelial cell proliferation was significantly blocked in mice lacking eNOS, and EMG-2-induced endothelial cell sprouting was significantly reduced in aortic vessels isolated from eNOS-deficient mice. Finally, pericyte recruitment to endothelial cells and vascular smooth muscle cell coverage to blood vessels were attenuated in mice lacking eNOS. Taken together, we suggest that the endothelial cell function and blood vessel maturation are regulated by eNOS during retinal angiogenesis. PMID:27610040

  2. Regulation of retinal angiogenesis by endothelial nitric oxide synthase signaling pathway

    PubMed Central

    Ha, Jung Min; Jin, Seo Yeon; Lee, Hye Sun; Shin, Hwa Kyoung; Lee, Dong Hyung; Song, Sang Heon; Kim, Chi Dae

    2016-01-01

    Angiogenesis plays an essential role in embryo development, tissue repair, inflammatory diseases, and tumor growth. In the present study, we showed that endothelial nitric oxide synthase (eNOS) regulates retinal angiogenesis. Mice that lack eNOS showed growth retardation, and retinal vessel development was significantly delayed. In addition, the number of tip cells and filopodia length were significantly reduced in mice lacking eNOS. Retinal endothelial cell proliferation was significantly blocked in mice lacking eNOS, and EMG-2-induced endothelial cell sprouting was significantly reduced in aortic vessels isolated from eNOS-deficient mice. Finally, pericyte recruitment to endothelial cells and vascular smooth muscle cell coverage to blood vessels were attenuated in mice lacking eNOS. Taken together, we suggest that the endothelial cell function and blood vessel maturation are regulated by eNOS during retinal angiogenesis. PMID:27610040

  3. Regulation of retinal angiogenesis by endothelial nitric oxide synthase signaling pathway

    PubMed Central

    Ha, Jung Min; Jin, Seo Yeon; Lee, Hye Sun; Shin, Hwa Kyoung; Lee, Dong Hyung; Song, Sang Heon; Kim, Chi Dae

    2016-01-01

    Angiogenesis plays an essential role in embryo development, tissue repair, inflammatory diseases, and tumor growth. In the present study, we showed that endothelial nitric oxide synthase (eNOS) regulates retinal angiogenesis. Mice that lack eNOS showed growth retardation, and retinal vessel development was significantly delayed. In addition, the number of tip cells and filopodia length were significantly reduced in mice lacking eNOS. Retinal endothelial cell proliferation was significantly blocked in mice lacking eNOS, and EMG-2-induced endothelial cell sprouting was significantly reduced in aortic vessels isolated from eNOS-deficient mice. Finally, pericyte recruitment to endothelial cells and vascular smooth muscle cell coverage to blood vessels were attenuated in mice lacking eNOS. Taken together, we suggest that the endothelial cell function and blood vessel maturation are regulated by eNOS during retinal angiogenesis.

  4. Rapid road repair vehicle

    DOEpatents

    Mara, L.M.

    1998-05-05

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find at the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was not heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past. 2 figs.

  5. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  6. DNA Mismatch Repair

    PubMed Central

    MARINUS, M. G.

    2014-01-01

    DNA mismatch repair functions to correct replication errors in newly synthesized DNA and to prevent recombination between related, but not identical (homeologous), DNA sequences. The mechanism of mismatch repair is best understood in Escherichia coli and is the main focus of this review. The early genetic studies of mismatch repair are described as a basis for the subsequent biochemical characterization of the system. The effects of mismatch repair on homologous and homeologous recombination are described. The relationship of mismatch repair to cell toxicity induced by various drugs is included. The VSP (Very Short Patch) repair system is described in detail. PMID:26442827

  7. DNA repair genes in the Megavirales pangenome.

    PubMed

    Blanc-Mathieu, Romain; Ogata, Hiroyuki

    2016-06-01

    The order 'Megavirales' represents a group of eukaryotic viruses with a large genome encoding a few hundred up to two thousand five hundred genes. Several members of Megavirales possess genes involved in major DNA repair pathways. Some of these genes were likely inherited from an ancient virus world and some others were derived from the genomes of their hosts. Here we examine molecular phylogenies of key DNA repair enzymes in light of recent hypotheses on the origin of Megavirales, and propose that the last common ancestors of the individual families of the order Megavirales already possessed DNA repair functions to achieve and maintain a moderately large genome and that this repair capacity gradually increased, in a family-dependent manner, during their recent evolution.

  8. Repair material properties for effective structural application

    SciTech Connect

    Mangat, P.S.; Limbachiya, M.C.

    1997-04-01

    Strength and engineering properties of three generic repair materials which are likely to influence long-term performance of repaired concrete structures were studied. Measured properties include strength, stiffness, shrinkage and creep deformations, together with the complete compressive stress-strain characteristics including post-cracking behavior. The repair materials considered in this investigation are commercially available and widely used. These included a high performance non-shrinkable concrete, a mineral based cementitious material with no additives or coarse aggregate size particles, and a cementitious mortar containing styrene acrylic copolymer with fiber additives. Performance comparisons are also made between these materials and plain concrete mixes of similar strength and stiffness, suitable for repair applications. The results show that shrinkage of the repair materials was significantly greater than the shrinkage of normal concrete. Moreover, the shrinkage of those modified with a polymer admixture was found to be very sensitive to the relative humidity of the exposure compared to normal concrete. The post-peak strain capacity of the material modified with a polymer admixture was markedly improved leading to a more pronounced falling branch of stress-strain curve. The ultimate stress level (at a maximum load) of specially formulated repair materials varies significantly, the lowest ultimate stress being recorded for the porous mineral-based material. The inclusion of aggregates improves the mechanical properties and dimensional stability of repair materials.

  9. Laparoscopic Inguinal Hernia Repair

    MedlinePlus

    ... Some hernia repairs are performed using a small telescope known as a laparoscope. If your surgeon has ... in the abdominal wall (muscle) using small incisions, telescopes and a patch (mesh). Laparoscopic repair offers a ...

  10. Eye muscle repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000111.htm Eye muscle repair - discharge To use the sharing features on ... enable JavaScript. You or your child had eye muscle repair surgery to correct eye muscle problems that ...

  11. Hydrocele repair - series (image)

    MedlinePlus

    ... vaginalis into the scrotum. This is called an inguinal hernia. If a hydrocele persists past the first six ... months of life, it should be surgically repaired. Inguinal hernia in infants is usually repaired within the first ...

  12. DNA repair activity in fish and interest in ecotoxicology: a review.

    PubMed

    Kienzler, Aude; Bony, Sylvie; Devaux, Alain

    2013-06-15

    The knowledge of DNA repair in a target species is of first importance as it is the primary line of defense against genotoxicants, and a better knowledge of DNA repair capacity in fish could help to interpret genotoxicity data and/or assist in the choice of target species, developmental stage and tissues to focus on, both for environmental biomonitoring studies and DNA repair testing. This review focuses in a first part on what is presently known on a mechanistic basis, about the various DNA repair systems in fish, in vivo and in established cell lines. Data on base excision repair (BER), direct reversal with O⁶-alkylguanine transferase and double strand breaks repair, although rather scarce, are being reviewed, as well as nucleotide excision repair (NER) and photoreactivation repair (PER), which are by far the most studied repair mechanisms in fish. Most of these repair mechanisms seem to be strongly species and tissue dependent; they also depend on the developmental stage of the organisms. BER is efficient in vivo, although no data has been found on in vitro models. NER activity is quite low or even inexistent depending on the studies; however this lack is partly compensated by a strong PER activity, especially in early developmental stage. In a second part, a survey of the ecotoxicological studies integrating DNA repair as a parameter responding to single or mixture of contaminant is realized. Three main approaches are being used: the measurement of DNA repair gene expression after exposure, although it has not yet been clearly established whether gene expression is indicative of repair capacity; the monitoring of DNA damage removal by following DNA repair kinetics; and the modulation of DNA repair activity following exposure in situ, in order to assess the impact of exposure history on DNA repair capacity. Since all DNA repair processes are possible targets for environmental pollutants, we can also wonder at which extent such a modulation of repair capacities

  13. Bone marrow-derived Kruppel-like Factor 10 Controls Re-endothelialization in Response to Arterial Injury

    PubMed Central

    Wara, Akm Khyrul; Manica, Andre; Marchini, Julio F.; Sun, Xinghui; Icli, Basak; Tesmenitsky, Yevgenia; Croce, Kevin; Feinberg, Mark W.

    2013-01-01

    Objective The objective of this study was to investigate the role of Kruppel-like factor (KLF) 10, a zinc-finger transcription factor, in bone marrow-derived cell responses to arterial endothelial injury. Accumulating evidence indicates that bone marrow-derived progenitors are recruited to sites of vascular injury and contribute to endothelial repair. Approach and Results In response to carotid artery endothelial denudation, KLF10 mRNA expression was markedlyincreased in both bone marrow and circulating lin− progenitor cells. To examine the specific role for KLF10 in arterial re-endothelialization, we used two models of endothelial denudation (wire- and thermal-induced injury) of the carotid artery in WT and KLF10−/− mice. WT mice displayed higher areas of re-endothelialization compared to KLF10−/− mice following endothelial injury using either method. Bone marrow (BM) transplant studies revealed that re-constitution of KLF10−/− mice with WT BM fully rescued the defect in re-endothelialization and increased lin−CD34+KDR+ progenitors in the blood and injured carotid arteries. Conversely, reconstitution of WT mice with KLF10−/−BM re-capitulated the defects in re-endothelialization and peripheral cell progenitors. The media from cultured KLF10−/− BM progenitors was markedly inefficient at promoting endothelial cell growth and migration compared to the media from WT progenitors, indicative of defective paracrine trophic effects from KLF10−/− BM progenitors. Finally, BM-derived KLF10−/− lin− progenitors from reconstituted mice had reduced CXCR4 expression and impaired migratory responses. Conclusions Collectively, these observations demonstrate a protective role for BM-derived KLF10 in paracrine and homing responses important to arterial endothelial injury and highlight KLF10 as a possible therapeutic target to promote endothelial repair in vascular disease states. PMID:23685559

  14. microRNAs as Pharmacological Targets in Endothelial Cell Function and Dysfunction

    PubMed Central

    Chamorro-Jorganes, Aránzazu; Araldi, Elisa; Suárez, Yajaira

    2013-01-01

    Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative, migratory and morphogenic capacities of endothelial cells, as well as control of leukocyte trafficking. MicroRNAs (miRNAs) are short non-coding RNAs that have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level. This review summarizes the latest insights in the identification of endothelial-specific miRNAs and their targets, as well as their roles in controlling endothelial cell functions in both autocrine and paracrine manner. In addition, we discuss the therapeutic potential for the treatment of endothelial cell dysfunction and associated vascular pathophysiological conditions. PMID:23603154

  15. Improving cardiovascular outcomes in rheumatic diseases: therapeutic potential of circulating endothelial progenitor cells.

    PubMed

    Reynolds, John A; Robertson, Abigail C; Bruce, Ian N; Alexander, M Yvonne

    2014-05-01

    Patients with Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) have a significantly increased risk of cardiovascular disease (CVD). The reason for this is unclear but may be due, at least in part, to the failure of endothelial repair mechanisms. Over the last 15 years there has been much interest in the mechanisms of endothelial renewal and its potential as a therapy for CVD. In the circulation there are two distinct populations of cells; myeloid angiogenic cells (MACs) which augment repair by the paracrine secretion of angiogenic factors, and outgrowth endothelial cells (OECs) which are true endothelial progenitor cells (EPCs) and promote vasculogenesis by differentiating into mature endothelium. There are marked abnormalities in the number and function of these cells in patients with RA and SLE. Inflammatory cytokines including interferon-alpha (IFNα) and tumour-necrosis factor alpha (TNFα) both impair MAC and OEC function ex vivo and may therefore contribute to the CVD risk in these patients. Whilst administration of mononuclear cells, MACs and other progenitors has improved cardiovascular outcomes in the acute setting, this is not a viable option in chronic disease. The pharmacological manipulation of MAC/OEC function in vivo however has the potential to significantly improve endothelial repair and thus reduce CVD in this high risk population. PMID:24333265

  16. Improving cardiovascular outcomes in rheumatic diseases: therapeutic potential of circulating endothelial progenitor cells.

    PubMed

    Reynolds, John A; Robertson, Abigail C; Bruce, Ian N; Alexander, M Yvonne

    2014-05-01

    Patients with Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) have a significantly increased risk of cardiovascular disease (CVD). The reason for this is unclear but may be due, at least in part, to the failure of endothelial repair mechanisms. Over the last 15 years there has been much interest in the mechanisms of endothelial renewal and its potential as a therapy for CVD. In the circulation there are two distinct populations of cells; myeloid angiogenic cells (MACs) which augment repair by the paracrine secretion of angiogenic factors, and outgrowth endothelial cells (OECs) which are true endothelial progenitor cells (EPCs) and promote vasculogenesis by differentiating into mature endothelium. There are marked abnormalities in the number and function of these cells in patients with RA and SLE. Inflammatory cytokines including interferon-alpha (IFNα) and tumour-necrosis factor alpha (TNFα) both impair MAC and OEC function ex vivo and may therefore contribute to the CVD risk in these patients. Whilst administration of mononuclear cells, MACs and other progenitors has improved cardiovascular outcomes in the acute setting, this is not a viable option in chronic disease. The pharmacological manipulation of MAC/OEC function in vivo however has the potential to significantly improve endothelial repair and thus reduce CVD in this high risk population.

  17. A Role for the Long Noncoding RNA SENCR in Commitment and Function of Endothelial Cells.

    PubMed

    Boulberdaa, Mounia; Scott, Elizabeth; Ballantyne, Margaret; Garcia, Raquel; Descamps, Betty; Angelini, Gianni D; Brittan, Mairi; Hunter, Amanda; McBride, Martin; McClure, John; Miano, Joseph M; Emanueli, Costanza; Mills, Nicholas L; Mountford, Joanne C; Baker, Andrew H

    2016-05-01

    Despite the increasing importance of long noncoding RNA in physiology and disease, their role in endothelial biology remains poorly understood. Growing evidence has highlighted them to be essential regulators of human embryonic stem cell differentiation. SENCR, a vascular-enriched long noncoding RNA, overlaps the Friend Leukemia Integration virus 1 (FLI1) gene, a regulator of endothelial development. Therefore, we wanted to test the hypothesis that SENCR may contribute to mesodermal and endothelial commitment as well as in endothelial function. We thus developed new differentiation protocols allowing generation of endothelial cells from human embryonic stem cells using both directed and hemogenic routes. The expression of SENCR was markedly regulated during endothelial commitment using both protocols. SENCR did not control the pluripotency of pluripotent cells; however its overexpression significantly potentiated early mesodermal and endothelial commitment. In human umbilical endothelial cell (HUVEC), SENCR induced proliferation, migration, and angiogenesis. SENCR expression was altered in vascular tissue and cells derived from patients with critical limb ischemia and premature coronary artery disease compared to controls. Here, we showed that SENCR contributes to the regulation of endothelial differentiation from pluripotent cells and controls the angiogenic capacity of HUVEC. These data give novel insight into the regulatory processes involved in endothelial development and function.

  18. A Role for the Long Noncoding RNA SENCR in Commitment and Function of Endothelial Cells

    PubMed Central

    Boulberdaa, Mounia; Scott, Elizabeth; Ballantyne, Margaret; Garcia, Raquel; Descamps, Betty; Angelini, Gianni D; Brittan, Mairi; Hunter, Amanda; McBride, Martin; McClure, John; Miano, Joseph M; Emanueli, Costanza; Mills, Nicholas L; Mountford, Joanne C; Baker, Andrew H

    2016-01-01

    Despite the increasing importance of long noncoding RNA in physiology and disease, their role in endothelial biology remains poorly understood. Growing evidence has highlighted them to be essential regulators of human embryonic stem cell differentiation. SENCR, a vascular-enriched long noncoding RNA, overlaps the Friend Leukemia Integration virus 1 (FLI1) gene, a regulator of endothelial development. Therefore, we wanted to test the hypothesis that SENCR may contribute to mesodermal and endothelial commitment as well as in endothelial function. We thus developed new differentiation protocols allowing generation of endothelial cells from human embryonic stem cells using both directed and hemogenic routes. The expression of SENCR was markedly regulated during endothelial commitment using both protocols. SENCR did not control the pluripotency of pluripotent cells; however its overexpression significantly potentiated early mesodermal and endothelial commitment. In human umbilical endothelial cell (HUVEC), SENCR induced proliferation, migration, and angiogenesis. SENCR expression was altered in vascular tissue and cells derived from patients with critical limb ischemia and premature coronary artery disease compared to controls. Here, we showed that SENCR contributes to the regulation of endothelial differentiation from pluripotent cells and controls the angiogenic capacity of HUVEC. These data give novel insight into the regulatory processes involved in endothelial development and function. PMID:26898221

  19. Endothelial dysfunction correlates with decompression bubbles in rats.

    PubMed

    Zhang, Kun; Wang, Dong; Jiang, Zhongxin; Ning, Xiaowei; Buzzacott, Peter; Xu, Weigang

    2016-09-12

    Previous studies have documented that decompression led to endothelial dysfunction with controversial results. This study aimed to clarify the relationship between endothelial dysfunction, bubble formation and decompression rate. Rats were subjected to simulated air dives with one of four decompression rates: one slow and three rapid. Bubble formation was detected ultrasonically following decompression for two hours, before measurement of endothelial related indices. Bubbles were found in only rapid-decompressed rats and the amount correlated with decompression rate with significant variability. Serum levels of ET-1, 6-keto-PGF1α, ICAM-1, VCAM-1 and MDA, lung Wet/Dry weight ratio and histological score increased, serum NO decreased following rapid decompression. Endothelial-dependent vasodilatation to Ach was reduced in pulmonary artery rings among rapid-decompressed rats. Near all the above changes correlated significantly with bubble amounts. The results suggest that bubbles may be the causative agent of decompression-induced endothelial damage and bubble amount is of clinical significance in assessing decompression stress. Furthermore, serum levels of ET-1 and MDA may serve as sensitive biomarkers with the capacity to indicate endothelial dysfunction and decompression stress following dives.

  20. Fibronectin coating of oxygenator membranes enhances endothelial cell attachment

    PubMed Central

    2013-01-01

    Background Extracorporeal membrane oxygenation (ECMO) can replace the lungs’ gas exchange capacity in refractory lung failure. However, its limited hemocompatibility, the activation of the coagulation and complement system as well as plasma leakage and protein deposition hamper mid- to long-term use and have constrained the development of an implantable lung assist device. In a tissue engineering approach, lining the blood contact surfaces of the ECMO device with endothelial cells might overcome these limitations. As a first step towards this aim, we hypothesized that coating the oxygenator’s gas exchange membrane with proteins might positively influence the attachment and proliferation of arterial endothelial cells. Methods Sheets of polypropylene (PP), polyoxymethylpentene (TPX) and polydimethylsiloxane (PDMS), typical material used for oxygenator gas exchange membranes, were coated with collagen, fibrinogen, gelatin or fibronectin. Tissue culture treated well plates served as controls. Endothelial cell attachment and proliferation were analyzed for a period of 4 days by microscopic examination and computer assisted cell counting. Results Endothelial cell seeding efficiency is within range of tissue culture treated controls for fibronectin treated surfaces only. Uncoated membranes as well as all other coatings lead to lower cell attachment. A confluent endothelial cell layer develops on fibronectin coated PDMS and the control surface only. Conclusions Fibronectin increases endothelial cells’ seeding efficiency on different oxygenator membrane material. PDMS coated with fibronectin shows sustained cell attachment for a period of four days in static culture conditions. PMID:23356939

  1. Endothelial dysfunction correlates with decompression bubbles in rats.

    PubMed

    Zhang, Kun; Wang, Dong; Jiang, Zhongxin; Ning, Xiaowei; Buzzacott, Peter; Xu, Weigang

    2016-01-01

    Previous studies have documented that decompression led to endothelial dysfunction with controversial results. This study aimed to clarify the relationship between endothelial dysfunction, bubble formation and decompression rate. Rats were subjected to simulated air dives with one of four decompression rates: one slow and three rapid. Bubble formation was detected ultrasonically following decompression for two hours, before measurement of endothelial related indices. Bubbles were found in only rapid-decompressed rats and the amount correlated with decompression rate with significant variability. Serum levels of ET-1, 6-keto-PGF1α, ICAM-1, VCAM-1 and MDA, lung Wet/Dry weight ratio and histological score increased, serum NO decreased following rapid decompression. Endothelial-dependent vasodilatation to Ach was reduced in pulmonary artery rings among rapid-decompressed rats. Near all the above changes correlated significantly with bubble amounts. The results suggest that bubbles may be the causative agent of decompression-induced endothelial damage and bubble amount is of clinical significance in assessing decompression stress. Furthermore, serum levels of ET-1 and MDA may serve as sensitive biomarkers with the capacity to indicate endothelial dysfunction and decompression stress following dives. PMID:27615160

  2. Endothelial dysfunction correlates with decompression bubbles in rats

    PubMed Central

    Zhang, Kun; Wang, Dong; Jiang, Zhongxin; Ning, Xiaowei; Buzzacott, Peter; Xu, Weigang

    2016-01-01

    Previous studies have documented that decompression led to endothelial dysfunction with controversial results. This study aimed to clarify the relationship between endothelial dysfunction, bubble formation and decompression rate. Rats were subjected to simulated air dives with one of four decompression rates: one slow and three rapid. Bubble formation was detected ultrasonically following decompression for two hours, before measurement of endothelial related indices. Bubbles were found in only rapid-decompressed rats and the amount correlated with decompression rate with significant variability. Serum levels of ET-1, 6-keto-PGF1α, ICAM-1, VCAM-1 and MDA, lung Wet/Dry weight ratio and histological score increased, serum NO decreased following rapid decompression. Endothelial-dependent vasodilatation to Ach was reduced in pulmonary artery rings among rapid-decompressed rats. Near all the above changes correlated significantly with bubble amounts. The results suggest that bubbles may be the causative agent of decompression–induced endothelial damage and bubble amount is of clinical significance in assessing decompression stress. Furthermore, serum levels of ET-1 and MDA may serve as sensitive biomarkers with the capacity to indicate endothelial dysfunction and decompression stress following dives. PMID:27615160

  3. Overexpression of LOXIN Protects Endothelial Progenitor Cells From Apoptosis Induced by Oxidized Low Density Lipoprotein.

    PubMed

    Veas, Carlos; Jara, Casandra; Willis, Naomi D; Pérez-Contreras, Karen; Gutierrez, Nicolas; Toledo, Jorge; Fernandez, Paulina; Radojkovic, Claudia; Zuñiga, Felipe A; Escudero, Carlos; Aguayo, Claudio

    2016-04-01

    Human endothelial progenitor cells (hEPC) are adult stem cells located in the bone marrow and peripheral blood. Studies have indicated that hEPC play an important role in the recovery and repair of injured endothelium, however, their quantity and functional capacity is reduced in several diseases including hypercholesterolemia. Recently, it has been demonstrated that hEPC express lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and its activation by oxidized low-density lipoprotein (ox-LDL) induces cellular dysfunction and apoptosis. This study aimed to investigate whether overexpression of LOXIN, a truncated isoform of LOX-1 that acts as a dominant negative, plays a protective role against ox-LDL-induced apoptosis in hEPC. Human endothelial progenitor cells exposed to ox-LDL showed a significant increase in LOX-1 expression, and apoptosis began at ox-LDL concentrations above 50 μg/mL. All hEPC apoptosed at 200 μg/mL ox-LDL. High LOXIN expression was generated using adenoviral systems in hEPC and SiHa cells transduced with 100 colony-forming units per cell. Transduced LOXIN localized to the plasma membrane and blocked ox-LDL uptake mediated by LOX-1. Overexpression of LOXIN protected hEPC from ox-LDL-induced apoptosis, and therefore maybe a novel way of improving hEPC function and quantity. These results suggest that adenoviral vectors of LOXIN may provide a possible treatment for diseases related to ox-LDL and vascular endothelium dysfunction, including atherosclerosis.

  4. Endothelial reconstitution by CD34+ progenitors derived from baboon embryonic stem cells.

    PubMed

    Shi, Qiang; Schatten, Gerald; Hodara, Vida; Simerly, Calvin; VandeBerg, John L

    2013-02-01

    In this study, we used a large non-human primate model, the baboon, to establish a step-wise protocol to generate CD34+ endothelial progenitor cells (EPCs) from embryonic stem cells (ESCs) and to demonstrate their reparative effects. Baboon ESCs were sequentially differentiated from embryoid body cultures for 9 days and then were specified into EPCs by culturing them in monolayer for 12 days. The resulting EPCs expressed CD34, CXCR4 and UEA-1, but neither CD31 nor CD117. The EPCs were able to form intact lumen structures when seeded on Matrigel, took up Dil-LDL, and responded to TNF-α. Angioblasts specified in EGM-2 medium and ECGS medium had 6.41 ± 1.16% (n = 3) and 9.32 ± 3.73% CD34+ cells (n = 3). The efficiency of generating CD34+ EPCs did not differ significantly from ECGS to EGM-2 culture media, however, angioblasts specified in ECGS medium expressed a higher percentage of CD34+/CXCR4+ cells (3.49 ± 1.32%, n = 3) than those specified in EGM-2 medium (0.49 ± 0.52%, n = 3). To observe their reparative capacity, we purified CD34+ progenitors after specification by EGM-2 medium; inoculated fluorescently labelled CD34+ EPCs into an arterial segment denuded of endothelium in an ex vivo system. After 14 days of ex vivo culture, the grafted cells had attached and integrated to the denuded surface; in addition, they had matured further and expressed terminally differentiated endothelial markers including CD31 and CD146. In conclusion, we have proved that specified CD34+ EPCs are promising therapeutic agents for repairing damaged vasculature.

  5. Overexpression of LOXIN Protects Endothelial Progenitor Cells From Apoptosis Induced by Oxidized Low Density Lipoprotein.

    PubMed

    Veas, Carlos; Jara, Casandra; Willis, Naomi D; Pérez-Contreras, Karen; Gutierrez, Nicolas; Toledo, Jorge; Fernandez, Paulina; Radojkovic, Claudia; Zuñiga, Felipe A; Escudero, Carlos; Aguayo, Claudio

    2016-04-01

    Human endothelial progenitor cells (hEPC) are adult stem cells located in the bone marrow and peripheral blood. Studies have indicated that hEPC play an important role in the recovery and repair of injured endothelium, however, their quantity and functional capacity is reduced in several diseases including hypercholesterolemia. Recently, it has been demonstrated that hEPC express lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and its activation by oxidized low-density lipoprotein (ox-LDL) induces cellular dysfunction and apoptosis. This study aimed to investigate whether overexpression of LOXIN, a truncated isoform of LOX-1 that acts as a dominant negative, plays a protective role against ox-LDL-induced apoptosis in hEPC. Human endothelial progenitor cells exposed to ox-LDL showed a significant increase in LOX-1 expression, and apoptosis began at ox-LDL concentrations above 50 μg/mL. All hEPC apoptosed at 200 μg/mL ox-LDL. High LOXIN expression was generated using adenoviral systems in hEPC and SiHa cells transduced with 100 colony-forming units per cell. Transduced LOXIN localized to the plasma membrane and blocked ox-LDL uptake mediated by LOX-1. Overexpression of LOXIN protected hEPC from ox-LDL-induced apoptosis, and therefore maybe a novel way of improving hEPC function and quantity. These results suggest that adenoviral vectors of LOXIN may provide a possible treatment for diseases related to ox-LDL and vascular endothelium dysfunction, including atherosclerosis. PMID:26771151

  6. DNA repair: From genome maintenance to biomarker and therapeutic target

    PubMed Central

    Jalal, Shadia; Earley, Jennifer N.; Turchi, John J.

    2011-01-01

    A critical link exists between an individual's ability to repair cellular DNA damage and cancer development, progression and response to therapy. Knowledge gained regarding the proteins involved and types of damage repaired by the individual DNA repair pathways has led to the development of a variety of assays aimed at determining an individual's DNA repair capacity. These assays and their use in the analysis of clinical samples has yielded useful though somewhat conflicting data. In this review article, we discuss the major DNA repair pathways, the proteins and genes required for each, assays used to assess activity and the relevant clinical studies to date. With the recent results from clinical trials targeting specific DNA repair proteins for the treatment of cancer, accurate, reproducible and relevant analysis of DNA repair takes on an even greater significance. We highlight the strengths and limitations of these DNA repair studies and assays with respect to the clinical assessment of DNA repair capacity to determine cancer development and response to therapy. PMID:21908578

  7. A platelet-rich plasma-based membrane as a periosteal substitute with enhanced osteogenic and angiogenic properties: a new concept for bone repair.

    PubMed

    El Backly, Rania M; Zaky, Samer H; Muraglia, Anita; Tonachini, Laura; Brun, Francesco; Canciani, Barbara; Chiapale, Danilo; Santolini, Federico; Cancedda, Ranieri; Mastrogiacomo, Maddalena

    2013-01-01

    The periosteum plays a pivotal role during bone development and repair contributing to bone vascularization and osteoprogenitor cells source. We propose a periosteal substitute engineered using a platelet-rich plasma (PRP) membrane incorporating autologous bone marrow-derived mesenchymal stem cells (PRP/BMSC gel membrane) to be wrapped around an osteoconductive scaffold for regeneration of compromised bone defects. The PRP/BMSC gel membrane was optimized using different compositions for optimal release of vascular endothelial growth factor (VEGF) and platelet derived growth factor-BB (PDGF-BB). Survival and proliferation of cells in the PRP gel membrane with time were confirmed in addition to their osteogenic capacity. Furthermore, to evaluate the possible effects of the PRP/BMSC gel membrane on surrounding progenitor cells in the injury area, we found that the PRP gel membrane products could significantly induce the migration of human endothelial cells in vitro, and increased the expression of bone morphogenetic protein 2 in cultured BMSC. These cells also secreted significant amounts of soluble proangiogenic factors, such as PDGF-BB, VEGF, and interleukin-8 (IL-8). Finally, the functionality of the PRP/BMSC gel membrane periosteal substitute for bone regeneration was tested in vivo both in an ectopic mouse model as well as in a rabbit segmental bone defect model providing evidence of its capacity to biomimic a periosteal response enhancing bone regeneration.

  8. Hematopoietic tissue repair under chronic low daily dose irradiation

    NASA Astrophysics Data System (ADS)

    Seed, T. M.

    The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). In our laboratory we have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3-26.3 cGy d^-1). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific (three major responding subgroups identified) and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup 1), the failure to augment basic repair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments (particularly marked within erythroid compartments) that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccommodated and either prone- or not prone to ML, subgroup 2 & 3) appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high-tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity. The kinetics of these repair-mediated, regenerative hematopoietic

  9. Participation of DNA repair in the response to 5-fluorouracil

    PubMed Central

    Wyatt, Michael D.; Wilson, David M.

    2008-01-01

    The anti-metabolite 5-fluorouracil (5-FU) is employed clinically to manage solid tumors including colorectal and breast cancer. Intracellular metabolites of 5-FU can exert cytotoxic effects via inhibition of thymidylate synthetase, or through incorporation into RNA and DNA, events that ultimately activate apoptosis. In this review, we cover the current data implicating DNA repair processes in cellular responsiveness to 5-FU treatment. Evidence points to roles for base excision repair (BER) and mismatch repair (MMR). However, mechanistic details remain unexplained, and other pathways have not been exhaustively interrogated. Homologous recombination is of particular interest, because it resolves unrepaired DNA intermediates not properly dealt with by BER or MMR. Furthermore, crosstalk among DNA repair pathways and S-phase checkpoint signaling has not been examined. Ongoing efforts aim to design approaches and reagents that (i) approximate repair capacity and (ii) mediate strategic regulation of DNA repair in order to improve the efficacy of current anti-cancer treatments. PMID:18979208

  10. Endothelial RIG-I activation impairs endothelial function

    SciTech Connect

    Asdonk, Tobias; Nickenig, Georg; Zimmer, Sebastian

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer RIG-I activation impairs endothelial function in vivo. Black-Right-Pointing-Pointer RIG-I activation alters HCAEC biology in vitro. Black-Right-Pointing-Pointer EPC function is affected by RIG-I stimulation in vitro. -- Abstract: Background: Endothelial dysfunction is a crucial part of the chronic inflammatory atherosclerotic process and is mediated by innate and acquired immune mechanisms. Recent studies suggest that pattern recognition receptors (PRR) specialized in immunorecognition of nucleic acids may play an important role in endothelial biology in a proatherogenic manner. Here, we analyzed the impact of endothelial retinoic acid inducible gene I (RIG-I) activation upon vascular endothelial biology. Methods and results: Wild type mice were injected intravenously with 32.5 {mu}g of the RIG-ligand 3pRNA (RNA with triphosphate at the 5 Prime end) or polyA control every other day for 7 days. In 3pRNA-treated mice, endothelium-depended vasodilation was significantly impaired, vascular oxidative stress significantly increased and circulating endothelial microparticle (EMP) numbers significantly elevated compared to controls. To gain further insight in RIG-I dependent endothelial biology, cultured human coronary endothelial cells (HCAEC) and endothelial progenitor cells (EPC) were stimulated in vitro with 3pRNA. Both cells types express RIG-I and react with receptor upregulation upon stimulation. Reactive oxygen species (ROS) formation is enhanced in both cell types, whereas apoptosis and proliferation is not significantly affected in HCAEC. Importantly, HCAEC release significant amounts of proinflammatory cytokines in response to RIG-I stimulation. Conclusion: This study shows that activation of the cytoplasmatic nucleic acid receptor RIG-I leads to endothelial dysfunction. RIG-I induced endothelial damage could therefore be an important pathway in atherogenesis.

  11. Restoring Akt1 activity in outgrowth endothelial cells from South Asian men rescues vascular reparative potential.

    PubMed

    Cubbon, Richard M; Yuldasheva, Nadira Y; Viswambharan, Hema; Mercer, Ben N; Baliga, Vivek; Stephen, Sam L; Askham, Jonathan; Sukumar, Piruthivi; Skromna, Anna; Mughal, Romana S; Walker, Andrew M N; Bruns, Alexander; Bailey, Marc A; Galloway, Stacey; Imrie, Helen; Gage, Matthew C; Rakobowchuk, Mark; Li, Jing; Porter, Karen E; Ponnambalam, Sreenivasan; Wheatcroft, Stephen B; Beech, David J; Kearney, Mark T

    2014-10-01

    Recent data suggest reduced indices of vascular repair in South Asian men, a group at increased risk of cardiovascular events. Outgrowth endothelial cells (OEC) represent an attractive tool to study vascular repair in humans and may offer potential in cell-based repair therapies. We aimed to define and manipulate potential mechanisms of impaired vascular repair in South Asian (SA) men. In vitro and in vivo assays of vascular repair and angiogenesis were performed using OEC derived from SA men and matched European controls, prior defining potentially causal molecular mechanisms. SA OEC exhibited impaired colony formation, migration, and in vitro angiogenesis, associated with decreased expression of the proangiogenic molecules Akt1 and endothelial nitric oxide synthase (eNOS). Transfusion of European OEC into immunodeficient mice after wire-induced femoral artery injury augmented re-endothelialization, in contrast with SA OEC and vehicle; SA OEC also failed to promote angiogenesis after induction of hind limb ischemia. Expression of constitutively active Akt1 (E17KAkt), but not green fluorescent protein control, in SA OEC increased in vitro angiogenesis, which was abrogated by a NOS antagonist. Moreover, E17KAkt expressing SA OEC promoted re-endothelialization of wire-injured femoral arteries, and perfusion recovery of ischemic limbs, to a magnitude comparable with nonmanipulated European OEC. Silencing Akt1 in European OEC recapitulated the functional deficits noted in SA OEC. Reduced signaling via the Akt/eNOS axis is causally linked with impaired OEC-mediated vascular repair in South Asian men. These data prove the principle of rescuing marked reparative dysfunction in OEC derived from these men.

  12. DNA repair in species with extreme lifespan differences.

    PubMed

    MacRae, Sheila L; Croken, Matthew McKnight; Calder, R B; Aliper, Alexander; Milholland, Brandon; White, Ryan R; Zhavoronkov, Alexander; Gladyshev, Vadim N; Seluanov, Andrei; Gorbunova, Vera; Zhang, Zhengdong D; Vijg, Jan

    2015-12-01

    Differences in DNA repair capacity have been hypothesized to underlie the great range of maximum lifespans among mammals. However, measurements of individual DNA repair activities in cells and animals have not substantiated such a relationship because utilization of repair pathways among animals--depending on habitats, anatomical characteristics, and life styles--varies greatly between mammalian species. Recent advances in high-throughput genomics, in combination with increased knowledge of the genetic pathways involved in genome maintenance, now enable a comprehensive comparison of DNA repair transcriptomes in animal species with extreme lifespan differences. Here we compare transcriptomes of liver, an organ with high oxidative metabolism and abundant spontaneous DNA damage, from humans, naked mole rats, and mice, with maximum lifespans of ~120, 30, and 3 years, respectively, with a focus on genes involved in DNA repair. The results show that the longer-lived species, human and naked mole rat, share higher expression of DNA repair genes, including core genes in several DNA repair pathways. A more systematic approach of signaling pathway analysis indicates statistically significant upregulation of several DNA repair signaling pathways in human and naked mole rat compared with mouse. The results of this present work indicate, for the first time, that DNA repair is upregulated in a major metabolic organ in long-lived humans and naked mole rats compared with short-lived mice. These results strongly suggest that DNA repair can be considered a genuine longevity assurance system. PMID:26729707

  13. DNA repair in species with extreme lifespan differences

    PubMed Central

    MacRae, Sheila L.; Croken, Matthew McKnight; Calder, R.B.; Aliper, Alexander; Milholland, Brandon; White, Ryan R.; Zhavoronkov, Alexander; Gladyshev, Vadim N.; Seluanov, Andrei; Gorbunova, Vera; Zhang, Zhengdong D.; Vijg, Jan

    2015-01-01

    Differences in DNA repair capacity have been hypothesized to underlie the great range of maximum lifespans among mammals. However, measurements of individual DNA repair activities in cells and animals have not substantiated such a relationship because utilization of repair pathways among animals—depending on habitats, anatomical characteristics, and life styles—varies greatly between mammalian species. Recent advances in high-throughput genomics, in combination with increased knowledge of the genetic pathways involved in genome maintenance, now enable a comprehensive comparison of DNA repair transcriptomes in animal species with extreme lifespan differences. Here we compare transcriptomes of liver, an organ with high oxidative metabolism and abundant spontaneous DNA damage, from humans, naked mole rats, and mice, with maximum lifespans of ∼120, 30, and 3 years, respectively, with a focus on genes involved in DNA repair. The results show that the longer-lived species, human and naked mole rat, share higher expression of DNA repair genes, including core genes in several DNA repair pathways. A more systematic approach of signaling pathway analysis indicates statistically significant upregulation of several DNA repair signaling pathways in human and naked mole rat compared with mouse. The results of this present work indicate, for the first time, that DNA repair is upregulated in a major metabolic organ in long-lived humans and naked mole rats compared with short-lived mice. These results strongly suggest that DNA repair can be considered a genuine longevity assurance system. PMID:26729707

  14. Optimality in DNA repair.

    PubMed

    Richard, Morgiane; Fryett, Matthew; Miller, Samantha; Booth, Ian; Grebogi, Celso; Moura, Alessandro

    2012-01-01

    DNA within cells is subject to damage from various sources. Organisms have evolved a number of mechanisms to repair DNA damage. The activity of repair enzymes carries its own risk, however, because the repair of two nearby lesions may lead to the breakup of DNA and result in cell death. We propose a mathematical theory of the damage and repair process in the important scenario where lesions are caused in bursts. We use this model to show that there is an optimum level of repair enzymes within cells which optimises the cell's response to damage. This optimal level is explained as the best trade-off between fast repair and a low probability of causing double-stranded breaks. We derive our results analytically and test them using stochastic simulations, and compare our predictions with current biological knowledge. PMID:21945337

  15. Transplantation of Human Pericyte Progenitor Cells Improves the Repair of Infarcted Heart Through Activation of an Angiogenic Program Involving Micro-RNA-132

    PubMed Central

    Katare, Rajesh; Riu, Federica; Mitchell, Kathryn; Gubernator, Miriam; Campagnolo, Paola; Cui, Yuxin; Fortunato, Orazio; Avolio, Elisa; Cesselli, Daniela; Beltrami, Antonio Paolo; Angelini, Gianni; Emanueli, Costanza; Madeddu, Paolo

    2013-01-01

    Rationale Pericytes are key regulators of vascular maturation, but their value for cardiac repair remains unknown. Objective We investigated the therapeutic activity and mechanistic targets of saphenous vein-derived pericyte progenitor cells (SVPs) in a mouse myocardial infarction (MI) model. Methods and Results SVPs have a low immunogenic profile and are resistant to hypoxia/starvation (H/S). Transplantation of SVPs into the peri-infarct zone of immunodeficient CD1/Foxn-1nu/nu or immunocompetent CD1 mice attenuated left ventricular dilatation and improved ejection fraction compared to vehicle. Moreover, SVPs reduced myocardial scar, cardiomyocyte apoptosis and interstitial fibrosis, improved myocardial blood flow and neovascularization, and attenuated vascular permeability. SVPs secrete vascular endothelial growth factor A, angiopoietin-1, and chemokines and induce an endogenous angiocrine response by the host, through recruitment of vascular endothelial growth factor B expressing monocytes. The association of donor- and recipient-derived stimuli activates the proangiogenic and prosurvival Akt/eNOS/Bcl-2 signaling pathway. Moreover, microRNA-132 (miR-132) was constitutively expressed and secreted by SVPs and remarkably upregulated, together with its transcriptional activator cyclic AMP response element-binding protein, on stimulation by H/S or vascular endothelial growth factor B. We next investigated if SVP-secreted miR-132 acts as a paracrine activator of cardiac healing. In vitro studies showed that SVP conditioned medium stimulates endothelial tube formation and reduces myofibroblast differentiation, through inhibition of Ras-GTPase activating protein and methyl-CpG-binding protein 2, which are validated miR-132 targets. Furthermore, miR-132 inhibition by antimiR-132 decreased SVP capacity to improve contractility, reparative angiogenesis, and interstitial fibrosis in infarcted hearts. Conclusion SVP transplantation produces long-term improvement of cardiac

  16. In vitro evaluation of endothelial exosomes as carriers for small interfering ribonucleic acid delivery.

    PubMed

    Banizs, Anna B; Huang, Tao; Dryden, Kelly; Berr, Stuart S; Stone, James R; Nakamoto, Robert K; Shi, Weibin; He, Jiang

    2014-01-01

    Exosomes, one subpopulation of nanosize extracellular vesicles derived from multivesicular bodies, ranging from 30 to 150 nm in size, emerged as promising carriers for small interfering ribonucleic acid (siRNA) delivery, as they are capable of transmitting molecular messages between cells through carried small noncoding RNAs, messenger RNAs, deoxyribonucleic acids, and proteins. Endothelial cells are involved in a number of important biological processes, and are a major source of circulating exosomes. In this study, we prepared exosomes from endothelial cells and evaluated their capacity to deliver siRNA into primary endothelial cells. Exosomes were isolated and purified by sequential centrifugation and ultracentrifugation from cultured mouse aortic endothelial cells. Similar to exosome particles from other cell sources, endothelial exosomes are nanometer-size vesicles, examined by both the NanoSight instrument and transmission electron microscopy. Enzyme-linked immunosorbent assay analysis confirmed the expression of two exosome markers: CD9 and CD63. Flow cytometry and fluorescence microscopy studies demonstrated that endothelial exosomes were heterogeneously distributed within cells. In a gene-silencing study with luciferase-expressing endothelial cells, exosomes loaded with siRNA inhibited luciferase expression by more than 40%. In contrast, siRNA alone and control siRNA only suppressed luciferase expression by less than 15%. In conclusion, we demonstrated that endothelial exosomes have the capability to accommodate and deliver short foreign nucleic acids into endothelial cells.

  17. In vitro evaluation of endothelial exosomes as carriers for small interfering ribonucleic acid delivery

    PubMed Central

    Banizs, Anna B; Huang, Tao; Dryden, Kelly; Berr, Stuart S; Stone, James R; Nakamoto, Robert K; Shi, Weibin; He, Jiang

    2014-01-01

    Exosomes, one subpopulation of nanosize extracellular vesicles derived from multivesicular bodies, ranging from 30 to 150 nm in size, emerged as promising carriers for small interfering ribonucleic acid (siRNA) delivery, as they are capable of transmitting molecular messages between cells through carried small noncoding RNAs, messenger RNAs, deoxyribonucleic acids, and proteins. Endothelial cells are involved in a number of important biological processes, and are a major source of circulating exosomes. In this study, we prepared exosomes from endothelial cells and evaluated their capacity to deliver siRNA into primary endothelial cells. Exosomes were isolated and purified by sequential centrifugation and ultracentrifugation from cultured mouse aortic endothelial cells. Similar to exosome particles from other cell sources, endothelial exosomes are nanometer-size vesicles, examined by both the NanoSight instrument and transmission electron microscopy. Enzyme-linked immunosorbent assay analysis confirmed the expression of two exosome markers: CD9 and CD63. Flow cytometry and fluorescence microscopy studies demonstrated that endothelial exosomes were heterogeneously distributed within cells. In a gene-silencing study with luciferase-expressing endothelial cells, exosomes loaded with siRNA inhibited luciferase expression by more than 40%. In contrast, siRNA alone and control siRNA only suppressed luciferase expression by less than 15%. In conclusion, we demonstrated that endothelial exosomes have the capability to accommodate and deliver short foreign nucleic acids into endothelial cells. PMID:25214786

  18. In Vitro Endothelialization Test of Biomaterials Using Immortalized Endothelial Cells

    PubMed Central

    Kono, Ken; Hiruma, Hitomi; Kobayashi, Shingo; Sato, Yoji; Tanaka, Masaru; Sawada, Rumi; Niimi, Shingo

    2016-01-01

    Functionalizing biomaterials with peptides or polymers that enhance recruitment of endothelial cells (ECs) can reduce blood coagulation and thrombosis. To assess endothelialization of materials in vitro, primary ECs are generally used, although the characteristics of these cells vary among the donors and change with time in culture. Recently, primary cell lines immortalized by transduction of simian vacuolating virus 40 large T antigen or human telomerase reverse transcriptase have been developed. To determine whether immortalized ECs can substitute for primary ECs in material testing, we investigated endothelialization on biocompatible polymers using three lots of primary human umbilical vein endothelial cells (HUVEC) and immortalized microvascular ECs, TIME-GFP. Attachment to and growth on polymer surfaces were comparable between cell types, but results were more consistent with TIME-GFP. Our findings indicate that TIME-GFP is more suitable for in vitro endothelialization testing of biomaterials. PMID:27348615

  19. Renewing solar science: The solar maximum repair mission

    NASA Technical Reports Server (NTRS)

    Neal, V.

    1985-01-01

    The purpose of the Solar Maximum Repair Mission is to restore the operational capacity of the satellite by replacing the attitude control system module and servicing two of the scientific instruments on board. The mission will demonstrate the satellite servicing capacity of the Space Shuttle for the first time.

  20. Brassinosteroids inhibit in vitro angiogenesis in human endothelial cells.

    PubMed

    Rárová, Lucie; Zahler, Stefan; Liebl, Johanna; Kryštof, Vladimír; Sedlák, David; Bartůněk, Petr; Kohout, Ladislav; Strnad, Miroslav

    2012-11-01

    Antiangiogenic activity of the brassinosteroid plant hormones (BRs) and their derivative cholestanon was investigated in human umbilical vein endothelial cells (HUVEC) and in human microvascular endothelial cells (HMEC-1). 24-Epibrassinolide and 28-homocastasterone from group of 21 tested natural BRs inhibited migration of HUVEC cells. Seven tested BRs decreased the number of tubes significantly. Synthetic analogue cholestanon inhibited angiogenesis in vitro more effectively than natural BRs. Because of the similarity of BRs to human steroids, we have also studied interactions of BRs with human steroid receptors. Synthetic BRs cholestanon showed agonistic effects on estrogen-receptor-α, estrogen-receptor-β and androgen receptor. Of the natural BRs, 24-epibrassinolide was found to be a weak antagonist of estrogen-receptor-α (ERα). Our results provide the first evidence that large group of BRs can inhibit in vitro angiogenesis of primary endothelial cells. BRs constitute a novel group of human steroid receptor activators or inhibitors with capacity to inhibit angiogenesis.

  1. The endothelial glycocalyx: a review of the vascular barrier.

    PubMed

    Alphonsus, C S; Rodseth, R N

    2014-07-01

    The endothelial glycocalyx is an important part of the vascular barrier. The glycocalyx is intimately linked to the homoeostatic functions of the endothelium. Damage to the glycocalyx precedes vascular pathology. In the first part of this paper, we have reviewed the structure, physiology and pathology of the endothelial glycocalyx, based on a literature search of the past five years. In the second part, we have systematically reviewed interventions to protect or repair the glycocalyx. Glycocalyx damage can be caused by hypervolaemia and hyperglycaemia and can be prevented by maintaining a physiological concentration of plasma protein, particularly albumin. Other interventions have been investigated in animal models: these require clinical research before their introduction into medical practice.

  2. Glutathione in Cerebral Microvascular Endothelial Biology and Pathobiology: Implications for Brain Homeostasis

    PubMed Central

    Li, Wei; Busu, Carmina; Circu, Magdalena L.; Aw, Tak Yee

    2012-01-01

    The integrity of the vascular endothelium of the blood-brain barrier (BBB) is central to cerebrovascular homeostasis. Given the function of the BBB as a physical and metabolic barrier that buffers the systemic environment, oxidative damage to the endothelial monolayer will have significant deleterious impact on the metabolic, immunological, and neurological functions of the brain. Glutathione (GSH) is a ubiquitous major thiol within mammalian cells that plays important roles in antioxidant defense, oxidation-reduction reactions in metabolic pathways, and redox signaling. The existence of distinct GSH pools within the subcellular organelles supports an elegant mode for independent redox regulation of metabolic processes, including those that control cell fate. GSH-dependent homeostatic control of neurovascular function is relatively unexplored. Significantly, GSH regulation of two aspects of endothelial function is paramount to barrier preservation, namely, GSH protection against oxidative endothelial cell injury and GSH control of postdamage cell proliferation in endothelial repair and/or wound healing. This paper highlights our current insights and hypotheses into the role of GSH in cerebral microvascular biology and pathobiology with special focus on endothelial GSH and vascular integrity, oxidative disruption of endothelial barrier function, GSH regulation of endothelial cell proliferation, and the pathological implications of GSH disruption in oxidative stress-associated neurovascular disorders, such as diabetes and stroke. PMID:22745639

  3. Vascular endothelial growth factor in human preterm lung.

    PubMed

    Lassus, P; Ristimäki, A; Ylikorkala, O; Viinikka, L; Andersson, S

    1999-05-01

    Endothelial cell damage is characteristic for respiratory distress syndrome and development of chronic lung disease. Vascular endothelial growth factor (VEGF) is an endothelial mitogen that takes part in the growth and repair of vascular endothelial cells. We measured VEGF in 189 tracheal aspirate samples (TAF), and in 24 plasma samples from 44 intubated preterm infants (gestational age, 27.3 +/- 2.0 wk; birth weight, 962 +/- 319 g) during their first postnatal week. VEGF in TAF increased from 25 +/- 12 pg/ml (mean +/- SEM) on Day 1 to 526 +/- 120 pg/ml on Day 7 (mean concentrations, 106 +/- 25 pg/ml on Days 1 to 3 and 342 +/- 36 pg/ml on Days 4 to 7). In plasma, mean concentration of VEGF during the first week was 48 +/- 6 pg/ml, with no increase observed. In TAF, higher VEGF was found in patients born to mothers with premature rupture of the membranes, or chorionamnionitis, whereas preeclampsia of the mother was associated with lower VEGF (all p < 0.05). In TAF, no correlations existed between VEGF and gestational age or birth weight, but a correlation existed between lecithin/sphengomyelin ratio and VEGF (p < 0.05). During Days 4 to 7 patients developing bronchopulmonary dysplasia (BPD) had lower VEGF in TAF than did those surviving without BPD (235 +/- 31 versus 383 +/- 50; p < 0.05). VEGF increased rapidly in the lungs of the preterm infant during the first days of life. VEGF may be indicative of pulmonary maturity and may participate in pulmonary repair after acute lung injury.

  4. [Medical significance of endothelial glycocalyx].

    PubMed

    Frati-Munari, Alberto C

    2013-01-01

    Endothelial glycocalyx is a layer composed by glycosaminoglycans, proteoglycans and glycoproteins attached to the vascular endothelial luminal surface. It has several physiological roles: shear stress mechanotransduction to the endothelial cells, regulation of fluids and macromolecules vascular permeability, of coagulation cascade activation and fibrinolysis, and protects the endothelium from platelets and leukocytes adhesion. In general, glycocalyx protects vascular wall against pathogenic insults. The glycocalyx may be damaged by abnormal shear stress, reactive oxygen species, hypernatremia, hyperglycemia, hypercholesterolemia and inflammatory molecules, resulting in endothelial dysfunction, enhanced vascular permeability, lipoproteins leakage to subendothelial space, activation of plasma coagulation, and increased adherence of platelets and leukocytes to the endothelial cells. Shredding of glycocalyx appears as an important initial step in the pathophysiology of vascular diseases.

  5. Glioma-associated endothelial cells show evidence of replicative senescence.

    PubMed

    Charalambous, Christiana; Virrey, Jenilyn; Kardosh, Adel; Jabbour, Mark N; Qazi-Abdullah, Lubna; Pen, Ligaya; Zidovetzki, Raphael; Schönthal, Axel H; Chen, Thomas C; Hofman, Florence M

    2007-04-01

    The innately programmed process of replicative senescence has been studied extensively with respect to cancer, but primarily from the perspective of tumor cells overcoming this stringent innate barrier and acquiring the capacity for unlimited proliferation. In this study, we focus on the potential role of replicative senescence affecting the non-transformed endothelial cells of the blood vessels within the tumor microenvironment. Based on the well-documented aberrant structural and functional features of blood vessels within solid tumors, we hypothesized that tumor-derived factors may lead to premature replicative senescence in tumor-associated brain endothelial cells (TuBEC). We show here that glioma tissue, but not normal brain tissue, contains cells that express the signature of replicative senescence, senescence-associated beta-galactosidase (SA-beta-gal), on CD31-positive endothelial cells. Primary cultures of human TuBEC stain for SA-beta-gal and exhibit characteristics of replicative senescence, including increased levels of the cell cycle inhibitors p21 and p27, increased resistance to cytotoxic drugs, increased growth factor production, and inability to proliferate. These data provide the first demonstration that tumor-derived brain endothelial cells may have reached an end-stage of differentiation known as replicative senescence and underscore the need for anti-angiogenic therapies to target this unique tumor-associated endothelial cell population.

  6. Glioma-associated endothelial cells show evidence of replicative senescence

    SciTech Connect

    Charalambous, Christiana; Virrey, Jenilyn; Kardosh, Adel; Jabbour, Mark N.; Qazi-Abdullah, Lubna; Pen, Ligaya; Zidovetzki, Raphael; Schoenthal, Axel H.; Chen, Thomas C.; Hofman, Florence M. . E-mail: hofman@usc.edu

    2007-04-01

    The innately programmed process of replicative senescence has been studied extensively with respect to cancer, but primarily from the perspective of tumor cells overcoming this stringent innate barrier and acquiring the capacity for unlimited proliferation. In this study, we focus on the potential role of replicative senescence affecting the non-transformed endothelial cells of the blood vessels within the tumor microenvironment. Based on the well-documented aberrant structural and functional features of blood vessels within solid tumors, we hypothesized that tumor-derived factors may lead to premature replicative senescence in tumor-associated brain endothelial cells (TuBEC). We show here that glioma tissue, but not normal brain tissue, contains cells that express the signature of replicative senescence, senescence-associated {beta}-galactosidase (SA-{beta}-gal), on CD31-positive endothelial cells. Primary cultures of human TuBEC stain for SA-{beta}-gal and exhibit characteristics of replicative senescence, including increased levels of the cell cycle inhibitors p21 and p27, increased resistance to cytotoxic drugs, increased growth factor production, and inability to proliferate. These data provide the first demonstration that tumor-derived brain endothelial cells may have reached an end-stage of differentiation known as replicative senescence and underscore the need for anti-angiogenic therapies to target this unique tumor-associated endothelial cell population.

  7. Angiocrine functions of organ-specific endothelial cells

    PubMed Central

    Rafii, Shahin; Butler, Jason M; Ding, Bi-Sen

    2016-01-01

    Preface Endothelial cells lining blood vessel capillaries are not just passive conduits for delivering blood. Tissue-specific endothelium establish specialized vascular niches that deploy specific sets of growth factors, known as angiocrine factors, which actively participate in inducing, specifying, patterning, and guiding organ regeneration and maintaining homeostasis and metabolism. Angiocrine factors upregulated in response to injury orchestrates self-renewal and differentiation of tissue-specific repopulating resident stem and progenitor cells into functional organs. Uncovering the precise mechanisms whereby physiological-levels of angiocrine factors are spatially and temporally produced, and distributed by organotypic endothelium to repopulating cells, will lay the foundation for driving organ repair without scarring. PMID:26791722

  8. [DNA repair--a fundamental factor in ageing and development of cancer].

    PubMed

    Rasmussen, Lene Juel; Stevnsner, Tinna; Bohr, Vilhelm A

    2006-06-12

    Advanced age and increased incidence of many illnesses such as cancer are closely linked. The reasons for such a link are numerous but one important factor is DNA repair. DNA repair pathways in both nuclei and mitochondria ensure that genomic instability is minimised, thus preventing transformation and premature cellular decay. However, overall cellular DNA repair capacity decreases with age; moreover, some individuals are born with defects in repair systems. The resulting lower capacity for repair of DNA damage increases mutation load and changes normal cellular functions such as transcription, thereby contributing to the ageing process as well to the onset of various cancers. DNA repair capacity is an important cellular marker that should be considered as a standard clinical test.

  9. Laparoscopic lumbar hernia repair.

    PubMed

    Madan, Atul K; Ternovits, Craig A; Speck, Karen E; Pritchard, F Elizabeth; Tichansky, David S

    2006-04-01

    Lumbar hernias are rare clinical entities that often pose a challenge for repair. Because of the surrounding anatomy, adequate surgical herniorraphy is often difficult. Minimally invasive surgery has become an option for these hernias. Herein, we describe two patients with lumbar hernias (one with a recurrent traumatic hernia and one with an incisional hernia). Both of these hernias were successfully repaired laparoscopically.

  10. Snowmobile Repair. Teacher Edition.

    ERIC Educational Resources Information Center

    Hennessy, Stephen S.; Conrad, Rex

    This teacher's guide contains 14 units on snowmobile repair: (1) introduction to snowmobile repair; (2) skis, front suspension, and steering; (3) drive clutch; (4) drive belts; (5) driven clutch; (6) chain drives; (7) jackshafts and axles; (8) rear suspension; (9) tracks; (10) shock absorbers; (11) brakes; (12) engines; (13) ignition and…

  11. [Assessment of legal capacity and testamentary capacity].

    PubMed

    Dreßing, H; Foerster, K; Leygraf, J; Schneider, F

    2014-11-01

    The assessment of legal capacity and testamentary capacity require thorough knowledge of the legal framework and the relevant case law. This paper explains the concept of the legal capacity to contract and the concept of testamentary capacity with respect to German civil law. The relevance of major mental disorders for the assessment of legal capacity and testamentary capacity is discussed.

  12. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan

    2005-07-20

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  13. Isolating human DNA repair genes using rodent-cell mutants

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-03-23

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

  14. Liver Sinusoidal Endothelial Cells.

    PubMed

    Sørensen, Karen Kristine; Simon-Santamaria, Jaione; McCuskey, Robert S; Smedsrød, Bård

    2015-10-01

    The liver sinusoidal endothelial cell (LSEC) forms the fenestrated wall of the hepatic sinusoid and functions as a control post regulating and surveying the trafficking of molecules and cells between the liver parenchyma and the blood. The cell acts as a scavenger cell responsible for removal of potential dangerous macromolecules from blood, and is increasingly acknowledged as an important player in liver immunity. This review provides an update of the major functions of the LSEC, including its role in plasma ultrafiltration and regulation of the hepatic microcirculation, scavenger functions, immune functions, and role in liver aging, as well as issues that are either undercommunicated or confusingly dealt with in the literature. These include metabolic functions, including energy metabolic interplay between the LSEC and the hepatocyte, and adequate ways of identifying and distinguishing the cells.

  15. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-12-31

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  16. Long-term changes in corneal endothelial morphology following wounding in the cat.

    PubMed

    Ling, T L; Vannas, A; Holden, B A

    1988-09-01

    The cat eye was used to determine the long-term morphological changes in the corneal endothelium that occur after central endothelial wounding. Central corneal thickness was measured using ultrasonic pachometry. Specular microscopy and computer-assisted morphometry was used to quantify central and peripheral endothelial cell density (ECD), coefficient of variation (COV) and the mean and standard deviation of the shape factor (S) over an 18-month period. After endothelial wounding, there was a rapid increase in corneal thickness followed by a rapid nonlinear decline, reaching presurgical levels 35 days after wounding. Central cell density had decreased by 25% at 4 weeks after wounding. During the following 18 months, endothelial cell density in the central cornea increased slightly. The coefficient of variation had increased by 60% at 4 weeks after wounding. This recovered slowly and had reached control levels by 18 months. The mean shape factor was higher in the wounded eye throughout the 18 months, whereas the standard deviation of the shape factor recovered after 12 months. Peripheral ECD had decreased significantly by 12 months after wounding, while COV and the mean shape factor was not significantly affected. The standard deviation of the shape factor had also increased significantly in the peripheral cornea after 18 months. These findings suggest that following endothelial wounding in the cat, changes in endothelial morphology occur over the entire cornea. Endothelial cell density and the shape factor have not recovered to control values, even 18 months after wounding. This pattern of endothelial repair supports the mechanisms of cell movement suggested by Honda et al and confirm the similarities in endothelial response between cat and man. PMID:3417425

  17. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-08-17

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners

  18. Hematopoietic tissue repair under chronic low daily dose irradiation

    SciTech Connect

    Seed, T.M.

    1994-12-01

    The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). We have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3{minus}26.3 cGy d{sup {minus}1}). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup (1), the failure to augment basic m-pair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments particularly marked within erythroid compartments. that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccomodated and either prone- or not prone to ML, subgroup 2 & 3 appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high- tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity.

  19. The Histone Demethylase PHF8 Is Essential for Endothelial Cell Migration

    PubMed Central

    Gu, Lunda; Hitzel, Juliane; Moll, Franziska; Kruse, Christoph; Malik, Randa Abdel; Preussner, Jens; Looso, Mario; Leisegang, Matthias S.; Steinhilber, Dieter; Brandes, Ralf P.; Fork, Christian

    2016-01-01

    Epigenetic marks critically control gene expression and thus the cellular activity state. The functions of many epigenetic modifiers in the vascular system have not yet been studied. We screened for histone modifiers in endothelial cells and observed a fairly high expression of the histone plant homeodomain finger protein 8 (PHF8). Given its high expression, we hypothesize that this histone demethylase is important for endothelial cell function. Overexpression of PHF8 catalyzed the removal of methyl-groups from histone 3 lysine 9 (H3K9) and H4K20, whereas knockdown of the enzyme increased H3K9 methylation. Knockdown of PHF8 by RNAi also attenuated endothelial proliferation and survival. As a functional readout endothelial migration and tube formation was studied. PHF8 siRNA attenuated the capacity for migration and developing of capillary-like structures. Given the impact of PHF8 on cell cycle genes, endothelial E2F transcription factors were screened, which led to the identification of the gene repressor E2F4 to be controlled by PHF8. Importantly, PHF8 maintains E2F4 but not E2F1 expression in endothelial cells. Consistently, chromatin immunoprecipitation revealed that PHF8 reduces the H3K9me2 level at the E2F4 transcriptional start site, demonstrating a direct function of PHF8 in endothelial E2F4 gene regulation. Conclusion: PHF8 by controlling E2F4 expression maintains endothelial function. PMID:26751588

  20. EUVL Mask Blank Repair

    SciTech Connect

    Barty, A; Mirkarimi, P; Stearns, D G; Sweeney, D; Chapman, H N; Clift, M; Hector, S; Yi, M

    2002-05-22

    EUV mask blanks are fabricated by depositing a reflective Mo/Si multilayer film onto super-polished substrates. Small defects in this thin film coating can significantly alter the reflected field and introduce defects in the printed image. Ideally one would want to produce defect-free mask blanks; however, this may be very difficult to achieve in practice. One practical way to increase the yield of mask blanks is to effectively repair multilayer defects, and to this effect they present two complementary defect repair strategies for use on multilayer-coated EUVL mask blanks. A defect is any area on the mask which causes unwanted variations in EUV dose in the aerial image obtained in a printing tool, and defect repair is correspondingly defined as any strategy that renders a defect unprintable during exposure. The term defect mitigation can be adopted to describe any strategy which renders a critical defect non-critical when printed, and in this regard a non-critical defect is one that does not adversely affect device function. Defects in the patterned absorber layer consist of regions where metal, typically chrome, is unintentionally added or removed from the pattern leading to errors in the reflected field. There currently exists a mature technology based on ion beam milling and ion beam assisted deposition for repairing defects in the absorber layer of transmission lithography masks, and it is reasonable to expect that this technology will be extended to the repair of absorber defects in EUVL masks. However, techniques designed for the repair of absorber layers can not be directly applied to the repair of defects in the mask blank, and in particular the multilayer film. In this paper they present for the first time a new technique for the repair of amplitude defects as well as recent results on the repair of phase defects.

  1. Rapid road repair vehicle

    SciTech Connect

    Mara, L.M.

    1999-09-07

    Disclosed are improvements to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  2. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1999-01-01

    Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  3. Isolation and angiogenesis by endothelial progenitors in the fetal liver.

    PubMed

    Cherqui, Stephanie; Kurian, Sunil M; Schussler, Olivier; Hewel, Johannes A; Yates, John R; Salomon, Daniel R

    2006-01-01

    Endothelial progenitor cells (EPCs) have significant therapeutic potential. However, the low quantity of such cells available from bone marrow and their limited capacity to proliferate in culture make their use difficult. Here, we present the first definitive demonstration of the presence of true EPCs in murine fetal liver capable of forming blood vessels in vivo connected to the host's vasculature after transplantation. This population is particularly interesting because it can be obtained at high yield and has a high angiogenic capacity as compared with bone marrow-derived EPCs. The EPC capacity is contained within the CD31+Sca1+ cell subset. We demonstrate that these cells are dependent for survival and proliferation on a feeder cell monolayer derived from the fetal liver. In addition, we describe a novel and easy method for the isolation and ex vivo proliferation of these EPCs. Finally, we used gene expression profiling and tandem mass spectrometry proteomics to examine the fetal liver endothelial progenitors and the feeder cells to identify possible proangiogenic growth factor and endothelial differentiation-associated genes.

  4. Repairing Thermal Tiles

    NASA Technical Reports Server (NTRS)

    Mccain, C. R., Jr.; Feiler, C. W.

    1984-01-01

    Small chips and depression in surfaces of surface insulation tiles repaired using Ludox colloidal silica solution and silica powder. No waiting time necessary between mixing filler and using it. Patch cures quickly without heat being applied.

  5. Easily repairable networks

    NASA Astrophysics Data System (ADS)

    Fink, Thomas

    2015-03-01

    We introduce a simple class of distribution networks which withstand damage by being repairable instead of redundant. Instead of asking how hard it is to disconnect nodes through damage, we ask how easy it is to reconnect nodes after damage. We prove that optimal networks on regular lattices have an expected cost of reconnection proportional to the lattice length, and that such networks have exactly three levels of structural hierarchy. We extend our results to networks subject to repeated attacks, in which the repairs themselves must be repairable. We find that, in exchange for a modest increase in repair cost, such networks are able to withstand any number of attacks. We acknowledge support from the Defense Threat Reduction Agency, BCG and EU FP7 (Growthcom).

  6. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; Nancy Porter; Mike Sullivan; Chris Neary

    2004-04-12

    The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforced composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created to

  7. Imperforate anus repair - slideshow

    MedlinePlus

    ... presentations/100030.htm Imperforate anus repair - series—Normal anatomy To use the sharing features on this page, ... of 4 Overview In individuals with a normal anatomy, the large intestine (colon) empties into a pouch- ...

  8. Timpani Repair and Maintenance.

    ERIC Educational Resources Information Center

    Combs, F. Michael

    1980-01-01

    Rather than focusing on specific brands of timpani, these guidelines for repair cover mechanical problems of a general nature: pedals, dents, unclear tone, and squeaking. Preventive maintenance is discussed. (Author/SJL)

  9. Eye muscle repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  10. Laparoscopic Ventral Hernia Repair

    MedlinePlus

    ... the likelihood of a hernia including persistent coughing, difficulty with bowel movements or urination, or frequent need for straining. What are the Advantages of Laparoscopic Ventral Hernia Repair? Keep reading... Page 1 of 2 1 2 » Brought to ...

  11. Human DNA repair genes.

    PubMed

    Wood, R D; Mitchell, M; Sgouros, J; Lindahl, T

    2001-02-16

    Cellular DNA is subjected to continual attack, both by reactive species inside cells and by environmental agents. Toxic and mutagenic consequences are minimized by distinct pathways of repair, and 130 known human DNA repair genes are described here. Notable features presently include four enzymes that can remove uracil from DNA, seven recombination genes related to RAD51, and many recently discovered DNA polymerases that bypass damage, but only one system to remove the main DNA lesions induced by ultraviolet light. More human DNA repair genes will be found by comparison with model organisms and as common folds in three-dimensional protein structures are determined. Modulation of DNA repair should lead to clinical applications including improvement of radiotherapy and treatment with anticancer drugs and an advanced understanding of the cellular aging process. PMID:11181991

  12. Planning Maintenance and Repairs.

    ERIC Educational Resources Information Center

    Fitzemeyer, Ted

    2001-01-01

    Discusses the use of school facility design as an aid to efficiently repairing and maintaining facility systems. Also presents details on facility design's influence in properly maintaining mechanical and electrical systems. (GR)

  13. Patent urachus repair

    MedlinePlus

    Patent urachal tube repair ... belly. Next, the surgeon will find the urachal tube and remove it. The bladder opening will be ... surgeon uses the tools to remove the urachal tube and close off the bladder and area where ...

  14. Achilles tendon repair

    MedlinePlus

    Achilles tendon rupture-surgery; Percutaneous Achilles tendon rupture repair ... To fix your torn Achilles tendon, the surgeon will: Make a cut down the back of your heel Make several small cuts rather than one large cut ...

  15. Repairing ceramic insulating tiles

    NASA Technical Reports Server (NTRS)

    Dunn, B. R.; Laymance, E. L.

    1980-01-01

    Fused-silica tiles containing large voids or gauges are repaired without adhesives by plug insertion method. Tiles are useful in conduits for high-temperature gases, in furnaces, and in other applications involving heat insulation.

  16. S1PR1 Tyr143 phosphorylation downregulates endothelial cell surface S1PR1 expression and responsiveness

    PubMed Central

    Chavez, Alejandra; Schmidt, Tracy Thennes; Yazbeck, Pascal; Rajput, Charu; Desai, Bhushan; Sukriti, Sukriti; Giantsos-Adams, Kristina; Knezevic, Nebojsa; Malik, Asrar B.; Mehta, Dolly

    2015-01-01

    ABSTRACT Activation of sphingosine-1-phosphate receptor 1 (S1PR1) plays a key role in repairing endothelial barrier function. We addressed the role of phosphorylation of the three intracellular tyrosine residues of S1PR1 in endothelial cells in regulating the receptor responsiveness and endothelial barrier function regulated by sphingosine 1-phosphate (S1P)-mediated activation of S1PR1. We demonstrated that phosphorylation of only Y143 site was required for S1PR1 internalization in response to S1P. Maximal S1PR1 internalization was seen in 20 min but S1PR1 returned to the cell surface within 1 h accompanied by Y143-dephosphorylation. Cell surface S1PR1 loss paralleled defective endothelial barrier enhancement induced by S1P. Expression of phospho-defective (Y143F) or phospho-mimicking (Y143D) mutants, respectively, failed to internalize or showed unusually high receptor internalization, consistent with the requirement of Y143 in regulating cell surface S1PR1 expression. Phosphorylation of the five S1PR1 C-terminal serine residues did not affect the role of Y143 phosphorylation in signaling S1PR1 internalization. Thus, rapid reduction of endothelial cell surface expression of S1PR1 subsequent to Y143 phosphorylation is a crucial mechanism of modulating S1PR1 signaling, and hence the endothelial barrier repair function of S1P. PMID:25588843

  17. Exosomes secreted by mesenchymal stem cells promote endothelial cell angiogenesis by transferring miR-125a.

    PubMed

    Liang, Xiaolei; Zhang, Lina; Wang, Shihua; Han, Qin; Zhao, Robert Chunhua

    2016-06-01

    Angiogenesis plays crucial roles in various physiological processes including wound healing and tissue repair. It requires a tight interaction between endothelial cells and their surrounding environment. Mesenchymal stem cells (MSCs), one of the non-endothelial cell types present in the perivascular environment, have been shown to secret exosomes to modulate intercellular communications between MSCs and their target cells. In this study, we initially isolated exosomes secreted by human adipose-derived MSCs (adMSC-Exo) and examined their roles in angiogenesis. We found that adMSC-Exo could be taken up by endothelial cells and significantly promote angiogenesis in vitro and in vivo Further study showed that miR-125a was enriched in adMSC-Exo, and repressed the expression of the angiogenic inhibitor delta-like 4 (DLL4) by targeting its 3' untranslated region. Additionally, adMSC-Exo and its exosomal transferred miR-125a could repress DLL4 expression and modulate endothelial cell angiogenesis through promoting formation of endothelial tip cells. In conclusion, our study indicates that adMSC-Exo can transfer miR-125a to endothelial cells and promote angiogenesis by repressing DLL4. adMSC-Exo, as a pro-angiogenic factor, might be a promising candidate for therapeutical tissue repair. PMID:27252357

  18. Hepatocyte growth factor is a potent angiogenic factor which stimulates endothelial cell motility and growth

    PubMed Central

    1992-01-01

    Hepatocyte Growth Factor (HGF, also known as Scatter Factor) is a powerful mitogen or motility factor in different cells, acting through the tyrosine kinase receptor encoded by the MET protooncogene. Endothelial cells express the MET gene and expose at the cell surface the mature protein (p190MET) made of a 50 kD (alpha) subunit disulfide linked to a 145-kD (beta) subunit. HGF binding to endothelial cells identifies two sites with different affinities. The higher affinity binding site (Kd = 0.35 nM) corresponds to the p190MET receptor. Sub- nanomolar concentrations of HGF, but not of a recombinant inactive precursor, stimulate the receptor kinase activity, cell proliferation and motility. HGF induces repairs of a wound in endothelial cell monolayer. HGF stimulates the scatter of endothelial cells grown on three-dimensional collagen gels, inducing an elongated phenotype. In the rabbit cornea, highly purified HGF promotes neovascularization at sub-nanomolar concentrations. HGF lacks activities related to hemostasis-thrombosis, inflammation and endothelial cells accessory functions. These data show that HGF is an in vivo potent angiogenic factor and in vitro induces endothelial cells to proliferate and migrate. PMID:1383237

  19. Repairing Foam Insulation

    NASA Technical Reports Server (NTRS)

    Corbin, J.; Buras, D.

    1986-01-01

    Large holes in polyurethane foam insulation repaired reliably by simple method. Little skill needed to apply method, used for overhead repairs as well as for those in other orientations. Plug positioned in hole to be filled and held in place with mounting fixture. Fresh liquid foam injected through plug to bond it in place. As foam cures and expands, it displaces plug outward. Protrusion later removed.

  20. Robotic inguinal hernia repair.

    PubMed

    Escobar Dominguez, Jose E; Gonzalez, Anthony; Donkor, Charan

    2015-09-01

    Inguinal hernias have been described throughout the history of medicine with many efforts to achieve the cure. Currently, with the advantages of minimally invasive surgery, new questions arise: what is going to be the best approach for inguinal hernia repair? Is there a real benefit with the robotic approach? Should minimally invasive hernia surgery be the standard of care? In this report we address these questions by describing our experience with robotic inguinal hernia repair. PMID:26153353

  1. Circulating Endothelial Microparticles: A Key Hallmark of Atherosclerosis Progression

    PubMed Central

    Panth, Nisha; Kim, Dong-Wook

    2016-01-01

    The levels of circulating microparticles (MPs) are raised in various cardiovascular diseases. Their increased level in plasma is regarded as a biomarker of alteration in vascular function. The prominent MPs present in blood are endothelial microparticles (EMPs) described as complex submicron (0.1 to 1.0 μm) vesicles like structure, released in response to endothelium cell activation or apoptosis. EMPs possess both physiological and pathological effects and may promote oxidative stress and vascular inflammation. EMPs release is triggered by inducer like angiotensin II, lipopolysaccharide, and hydrogen peroxide leading to the progression of atherosclerosis. However, there are multiple physiological pathways for EMPs generation like NADPH oxidase derived endothelial ROS formation, Rho kinase pathway, and mitogen-activated protein kinases. Endothelial dysfunction is a key initiating event in atherosclerotic plaque formation. Atheroemboli, resulting from ruptured carotid plaques, is a major cause of stroke. Increasing evidence suggests that EMPs play an important role in the pathogenesis of cardiovascular disease, acting as a marker of damage, either exacerbating disease progression or triggering a repair response. In this regard, it has been suggested that EMPs have the potential to act as biomarkers of disease status. This review aims to provide updated information of EMPs in relation to atherosclerosis pathogenesis. PMID:27066292

  2. Endothelial-regenerating cells: an expanding universe.

    PubMed

    Steinmetz, Martin; Nickenig, Georg; Werner, Nikos

    2010-03-01

    Atherosclerosis is the most common cause for cardiovascular diseases and is based on endothelial dysfunction. A growing body of evidence suggests the contribution of bone marrow-derived endothelial progenitor cells, monocytic cells, and mature endothelial cells to vessel formation and endothelial rejuvenation. To this day, various subsets of these endothelial-regenerating cells have been identified according to cellular origin, phenotype, and properties in vivo and in vitro. However, the definition and biology, especially of endothelial progenitor cells, is complex and under heavy debate. In this review, we focus on current definitions of endothelial progenitor cells, highlight the clinical relevance of endothelial-regenerating cells, and provide new insights into cell-cell interactions involved in endothelial cell rejuvenation.

  3. Disrupted Endothelial Cell Layer and Exposed Extracellular Matrix Proteins Promote Capture of Late Outgrowth Endothelial Progenitor Cells.

    PubMed

    Zhao, Jing; Mitrofan, Claudia-Gabriela; Appleby, Sarah L; Morrell, Nicholas W; Lever, Andrew M L

    2016-01-01

    Late outgrowth endothelial progenitor cells (LO-EPC) possess a high proliferative potential, differentiate into vascular endothelial cells (EC), and form networks, suggesting they play a role in vascular repair. However, due to their scarcity in the circulation there is a requirement for ex vivo expansion before they could provide a practical cell therapy and it is currently unclear if they would home and engraft to an injury site. Using an in vitro flow system we studied LO-EPC under simulated injury conditions including EC activation, ischaemia, disrupted EC integrity, and exposed basement membrane. Perfused LO-EPC adhered to discontinuous EC paracellularly at junctional regions between adjacent cells under shear stress 0.7 dyn/cm(2). The interaction was not adhesion molecule-dependent and not enhanced by EC activation. LO-EPC expressed high levels of the VE-Cadherin which may explain these findings. Ischaemia reperfusion injury decreased the interaction with LO-EPC due to cell retraction. LO-EPC interacted with exposed extracellular matrix (ECM) proteins, fibronectin and vitronectin. The interaction was mediated by integrins α5β3, αvβ1, and αvβ3. This study has demonstrated that an injured local environment presents sufficient adhesive signals to capture flow perfused LO-EPC in vitro and that LO-EPC have properties consistent with their potential role in vascular repair.

  4. Disrupted Endothelial Cell Layer and Exposed Extracellular Matrix Proteins Promote Capture of Late Outgrowth Endothelial Progenitor Cells.

    PubMed

    Zhao, Jing; Mitrofan, Claudia-Gabriela; Appleby, Sarah L; Morrell, Nicholas W; Lever, Andrew M L

    2016-01-01

    Late outgrowth endothelial progenitor cells (LO-EPC) possess a high proliferative potential, differentiate into vascular endothelial cells (EC), and form networks, suggesting they play a role in vascular repair. However, due to their scarcity in the circulation there is a requirement for ex vivo expansion before they could provide a practical cell therapy and it is currently unclear if they would home and engraft to an injury site. Using an in vitro flow system we studied LO-EPC under simulated injury conditions including EC activation, ischaemia, disrupted EC integrity, and exposed basement membrane. Perfused LO-EPC adhered to discontinuous EC paracellularly at junctional regions between adjacent cells under shear stress 0.7 dyn/cm(2). The interaction was not adhesion molecule-dependent and not enhanced by EC activation. LO-EPC expressed high levels of the VE-Cadherin which may explain these findings. Ischaemia reperfusion injury decreased the interaction with LO-EPC due to cell retraction. LO-EPC interacted with exposed extracellular matrix (ECM) proteins, fibronectin and vitronectin. The interaction was mediated by integrins α5β3, αvβ1, and αvβ3. This study has demonstrated that an injured local environment presents sufficient adhesive signals to capture flow perfused LO-EPC in vitro and that LO-EPC have properties consistent with their potential role in vascular repair. PMID:27413378

  5. Disrupted Endothelial Cell Layer and Exposed Extracellular Matrix Proteins Promote Capture of Late Outgrowth Endothelial Progenitor Cells

    PubMed Central

    Mitrofan, Claudia-Gabriela; Appleby, Sarah L.; Morrell, Nicholas W.; Lever, Andrew M. L.

    2016-01-01

    Late outgrowth endothelial progenitor cells (LO-EPC) possess a high proliferative potential, differentiate into vascular endothelial cells (EC), and form networks, suggesting they play a role in vascular repair. However, due to their scarcity in the circulation there is a requirement for ex vivo expansion before they could provide a practical cell therapy and it is currently unclear if they would home and engraft to an injury site. Using an in vitro flow system we studied LO-EPC under simulated injury conditions including EC activation, ischaemia, disrupted EC integrity, and exposed basement membrane. Perfused LO-EPC adhered to discontinuous EC paracellularly at junctional regions between adjacent cells under shear stress 0.7 dyn/cm2. The interaction was not adhesion molecule-dependent and not enhanced by EC activation. LO-EPC expressed high levels of the VE-Cadherin which may explain these findings. Ischaemia reperfusion injury decreased the interaction with LO-EPC due to cell retraction. LO-EPC interacted with exposed extracellular matrix (ECM) proteins, fibronectin and vitronectin. The interaction was mediated by integrins α5β3, αvβ1, and αvβ3. This study has demonstrated that an injured local environment presents sufficient adhesive signals to capture flow perfused LO-EPC in vitro and that LO-EPC have properties consistent with their potential role in vascular repair. PMID:27413378

  6. Junctional communication is induced in migrating capillary endothelial cells

    PubMed Central

    1989-01-01

    Using an in vitro model in which a confluent monolayer of capillary endothelial cells is mechanically wounded, gap junction-mediated intercellular communication has been studied by loading the cells with the fluorescent dye, Lucifer Yellow. Approximately 40-50% of the cells in a nonwounded confluent monolayer were coupled in groups of four to five cells (basal level). Basal levels of communication were also observed in sparse and preconfluent cultures, but were reduced in postconfluent monolayers. 30 min after wounding, coupling was markedly reduced between cells lining the wound. Communication at the wound was partially reestablished by 2 h, exceeded basal levels after 6 h and reached a maximum after 24 h, at which stage approximately 90% of the cells were coupled in groups of six to seven cells. When the wound had closed (after 8 d), the increase in communication was no longer observed. Induction of wound-associated communication was unaffected by exposure of the cells to the DNA synthesis inhibitor mitomycin C, but was prevented by the protein synthesis inhibitor, cycloheximide. The induction of wound-associated communication was also inhibited when migration was prevented by placing the cells immediately after wounding at 22 degrees C or after exposure to cytochalasin D, suggesting that the increase in communication is dependent on cells migrating into the wound area. In contrast, migration was not prevented when coupling was blocked by exposure of the cells to retinoic acid, although this agent did disrupt the characteristic sheet-like pattern of migration typically seen during endothelial repair. These results suggest that junctional communication may play an important role in wound repair, possibly by coordinating capillary endothelial cell migration. PMID:2592412

  7. Excision repair of UV radiation-induced DNA damage in Caenorhabditis elegans

    SciTech Connect

    Hartman, P.S.; Hevelone, J.; Dwarakanath, V.; Mitchell, D.L. )

    1989-06-01

    Radioimmunoassays were used to monitor the removal of antibody-binding sites associated with the two major UV radiation-induced DNA photoproducts (cyclobutane dimers and (6-4) photoproducts). Unlike with cultured human cells, where (6-4) photoproducts are removed more rapidly than cyclobutane dimers, the kinetics of repair were similar for both lesions. Repair capacity in wild type diminished throughout development. The radioimmunoassays were also employed to confirm the absence of photoreactivation in C. elegans. In addition, three radiation-sensitive mutants (rad-1, rad-2, rad-7) displayed normal repair capacities. An excision defect was much more pronounced in larvae than embryos in the fourth mutant tested (rad-3). This correlates with the hypersensitivity pattern of this mutant and suggests that DNA repair may be developmentally regulated in C. elegans. The mechanism of DNA repair in C. elegans as well as the relationship between the repair of specific photoproducts and UV radiation sensitivity during development are discussed.

  8. Haptoglobin phenotype may alter endothelial progenitor cell cluster formation in cerebral small vessel disease.

    PubMed

    Rouhl, R P W; van Oostenbrugge, R J; Damoiseaux, J G M C; Debrus-Palmans, L L; Theunissen, R O M F I H; Knottnerus, I L H; Staals, J E A; Delanghe, J R; Tervaert, J W Cohen; Lodder, J

    2009-02-01

    Cerebral small vessel disease results in silent ischemic lesions (SIL) among which is leukoaraiosis. In this process, endothelial damage is probably involved. Endothelial progenitor cells (EPC), are involved in endothelial repair. By restoring the damaged endothelium, EPC could mitigate SIL and cerebral small vessel disease. Haptoglobin 1-1, one of three phenotypes of haptoglobin, relates to SIL and may therefore attenuate the endothelial repair by EPC. Our aim was to quantify EPC number and function and to assess haptoglobin phenotype and its effect on EPC function in patients with a high prevalence of SIL: lacunar stroke patients. We assessed EPC In 42 lacunar stroke patients and 18 controls by flow cytometry and culture with fetal calf serum, patient and control serum. We determined haptoglobin phenotype and cultured EPC with the three different haptoglobin phenotypes. We found that EPC cluster counts were lower in patients (96.9 clusters/well +/- 83.4 (mean +/- SD)), especially in those with SIL (85.0 +/- 64.3), than in controls (174.4 +/- 112.2). Cluster formation was inhibited by patient serum, especially by SIL patient serum, but not by control serum. Patients with haptoglobin 1-1 had less clusters in culture, and when haptoglobin 1-1 was added to EPC cultures, cluster numbers were lower than with the other haptoglobin phenotypes. We conclude that lacunar stroke patients, especially those with SIL, have impaired EPC cluster formation, which may point at decreased endothelial repair potential. The haptoglobin 1-1 phenotype is likely a causative factor in this impairment. PMID:19355924

  9. Recent Progress in Endothelial Progenitor Cell Culture Systems: Potential for Stroke Therapy

    PubMed Central

    TAKIZAWA, Shunya; NAGATA, Eiichiro; NAKAYAMA, Taira; MASUDA, Haruchika; ASAHARA, Takayuki

    2016-01-01

    Endothelial progenitor cells (EPCs) participate in endothelial repair and angiogenesis due to their abilities to differentiate into endothelial cells and to secrete protective cytokines and growth factors. Consequently, there is considerable interest in cell therapy with EPCs isolated from peripheral blood to treat various ischemic injuries. Quality and quantity-controlled culture systems to obtain mononuclear cells enriched in EPCs with well-defined angiogenic and anti-inflammatory phenotypes have recently been developed, and increasing evidence from animal models and clinical trials supports the idea that transplantation of EPCs contributes to the regenerative process in ischemic organs and is effective for the therapy of ischemic cerebral injury. Here, we briefly describe the general characteristics of EPCs, and we review recent developments in culture systems and applications of EPCs and EPC-enriched cell populations to treat ischemic stroke. PMID:27041632

  10. The matricellular protein CCN1 regulates TNF-α induced vascular endothelial cell apoptosis.

    PubMed

    Zhang, Jin; Wu, Gongxiong; Dai, Haibin

    2016-01-01

    Due to the epidemic obesity and associated diabetes, the incidence of atherosclerosis is increasing worldwide. Atherosclerosis is a chronic inflammatory disease characterized by the hardening and narrowing of arteries with plaques that consist of inflammatory cells, dead endothelial cells, lipids, and often hyper proliferated vascular smooth muscle cells. During the development of atherosclerosis, vascular endothelial cell (EC) apoptosis induced by the adipokine tumor necrosis factor alpha (TNF-α), is an early event in the plaque formation. However, TNF-α alone is not sufficient to induce apoptosis of endothelial cells. Recent studies suggested that the matricellular protein CCN family member 1 (CCN1) involves in endothelial cell dysfunction besides its well-known angiogenic function during tissue repair by promoting vascular smooth muscle cells proliferation and migration. Herein, we explored the possibility and mechanism of CCN1 in TNF-α induced endothelial cells apoptosis. Both mRNA and protein levels of CCN1 are found up-regulated in endothelial cells after TNF-α treatment. In addition, overexpression of CCN1 promoted endothelial cell apoptosis in the presence of TNF-α. Furthermore, CCN1 directly up-regulated the expression of TNF-α-target genes, and this up-regulation required the activation of P53 and NF-κB both in vivo and in vitro. Taken together, CNN1 regulates TNF-α induced endothelial cells apoptosis that may underlie poor response to TNF-α therapy and hence may be a better therapeutic target for preventing vascular dysfunction in obesity.

  11. Effects of scuba diving on vascular repair mechanisms.

    PubMed

    Culic, Vedrana Cikes; Van Craenenbroeck, Emeline; Muzinic, Nikolina Rezic; Ljubkovic, Marko; Marinovic, Jasna; Conraads, Viviane; Dujic, Zeljko

    2014-01-01

    A single air dive causes transient endothelial dysfunction. Endothelial progenitor cells (EPCs) and circulating angiogenic cells (CAC) contribute synergistically to endothelial repair. In this study (1) the acute effects of diving on EPC numbers and CAC migration and (2) the influence of the gas mixture (air/nitrox-36) was investigated. Ten divers performed two dives to 18 meters on Day (D) 1 and D3, using air. After 15 days, dives were repeated with nitrox-36. Blood sampling took place before and immediately after diving. Circulating EPCs were quantified by flow cytometry, CAC migration of culture was assessed on D7. When diving on air, a trend for reduced EPC numbers is observed post-dive, which is persistent on D1 and D3. CAC migration tends to improve acutely following diving. These effects are more pronounced with nitrox-36 dives. Diving acutely affects EPC numbers and CAC function, and to a larger extent when diving with nitrox-36. The diving-induced oxidative stress may influence recruitment or survival of EPC. The functional improvement of CAC could be a compensatory mechanism to maintain endothelial homeostasis.

  12. Effects of scuba diving on vascular repair mechanisms.

    PubMed

    Culic, Vedrana Cikes; Van Craenenbroeck, Emeline; Muzinic, Nikolina Rezic; Ljubkovic, Marko; Marinovic, Jasna; Conraads, Viviane; Dujic, Zeljko

    2014-01-01

    A single air dive causes transient endothelial dysfunction. Endothelial progenitor cells (EPCs) and circulating angiogenic cells (CAC) contribute synergistically to endothelial repair. In this study (1) the acute effects of diving on EPC numbers and CAC migration and (2) the influence of the gas mixture (air/nitrox-36) was investigated. Ten divers performed two dives to 18 meters on Day (D) 1 and D3, using air. After 15 days, dives were repeated with nitrox-36. Blood sampling took place before and immediately after diving. Circulating EPCs were quantified by flow cytometry, CAC migration of culture was assessed on D7. When diving on air, a trend for reduced EPC numbers is observed post-dive, which is persistent on D1 and D3. CAC migration tends to improve acutely following diving. These effects are more pronounced with nitrox-36 dives. Diving acutely affects EPC numbers and CAC function, and to a larger extent when diving with nitrox-36. The diving-induced oxidative stress may influence recruitment or survival of EPC. The functional improvement of CAC could be a compensatory mechanism to maintain endothelial homeostasis. PMID:24851546

  13. Estetrol Modulates Endothelial Nitric Oxide Synthesis in Human Endothelial Cells

    PubMed Central

    Montt-Guevara, Maria Magdalena; Giretti, Maria Silvia; Russo, Eleonora; Giannini, Andrea; Mannella, Paolo; Genazzani, Andrea Riccardo; Genazzani, Alessandro David; Simoncini, Tommaso

    2015-01-01

    Estetrol (E4) is a natural human estrogen that is present at high concentrations during pregnancy. E4 has been reported to act as an endogenous estrogen receptor modulator, exerting estrogenic actions on the endometrium or the central nervous system but presenting antagonistic effects on the breast. Due to these characteristics, E4 is currently being developed for a number of clinical applications, including contraception and menopausal hormone therapy. Endothelial nitric oxide (NO) is a key player for vascular function and disease during pregnancy and throughout aging in women. Endothelial NO is an established target of estrogens that enhance its formation in human endothelial cells. We here addressed the effects of E4 on the activity and expression of the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells (HUVEC). E4 stimulated the activation of eNOS and NO secretion in HUVEC. E4 was significantly less effective compared to E2, and a peculiar concentration-dependent effect was found, with higher amounts of E4 being less effective than lower concentrations. When E2 was combined with E4, an interesting pattern was noted. E4 antagonized NO synthesis induced by pregnancy-like E2 concentrations. However, E4 did not impede the modest induction of NO synthesis associated with postmenopausal-like E2 levels. These results support the hypothesis that E4 may be a regulator of NO synthesis in endothelial cells and raise questions on its peculiar signaling in this context. Our results may be useful to interpret the role of E4 during human pregnancy and possibly to help develop this interesting steroid for clinical use. PMID:26257704

  14. Estetrol Modulates Endothelial Nitric Oxide Synthesis in Human Endothelial Cells.

    PubMed

    Montt-Guevara, Maria Magdalena; Giretti, Maria Silvia; Russo, Eleonora; Giannini, Andrea; Mannella, Paolo; Genazzani, Andrea Riccardo; Genazzani, Alessandro David; Simoncini, Tommaso

    2015-01-01

    Estetrol (E4) is a natural human estrogen that is present at high concentrations during pregnancy. E4 has been reported to act as an endogenous estrogen receptor modulator, exerting estrogenic actions on the endometrium or the central nervous system but presenting antagonistic effects on the breast. Due to these characteristics, E4 is currently being developed for a number of clinical applications, including contraception and menopausal hormone therapy. Endothelial nitric oxide (NO) is a key player for vascular function and disease during pregnancy and throughout aging in women. Endothelial NO is an established target of estrogens that enhance its formation in human endothelial cells. We here addressed the effects of E4 on the activity and expression of the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells (HUVEC). E4 stimulated the activation of eNOS and NO secretion in HUVEC. E4 was significantly less effective compared to E2, and a peculiar concentration-dependent effect was found, with higher amounts of E4 being less effective than lower concentrations. When E2 was combined with E4, an interesting pattern was noted. E4 antagonized NO synthesis induced by pregnancy-like E2 concentrations. However, E4 did not impede the modest induction of NO synthesis associated with postmenopausal-like E2 levels. These results support the hypothesis that E4 may be a regulator of NO synthesis in endothelial cells and raise questions on its peculiar signaling in this context. Our results may be useful to interpret the role of E4 during human pregnancy and possibly to help develop this interesting steroid for clinical use. PMID:26257704

  15. How cholesterol regulates endothelial biomechanics

    PubMed Central

    Hong, Zhongkui; Staiculescu, Marius C.; Hampel, Paul; Levitan, Irena; Forgacs, Gabor

    2012-01-01

    As endothelial cells form the barrier between blood flow and surrounding tissue, many of their functions depend on mechanical integrity, in particular those of the plasma membrane. As component and organizer of the plasma membrane, cholesterol is a regulator of cellular mechanical properties. Disruption of cholesterol balance leads to impairment of endothelial functions and eventually to disease. The mechanical properties of the membrane are strongly affected by the cytoskeleton. As Phosphatidylinositol-4,5-bisphosphate (PIP2) is a key mediator between the membrane and cytoskeleton, it also affects cellular biomechanical properties. Typically, PIP2 is concentrated in cholesterol-rich microdomains, such as caveolae and lipid rafts, which are particularly abundant in the endothelial plasma membrane. We investigated the connection between cholesterol and PIP2 by extracting membrane tethers from bovine aortic endothelial cells (BAEC) at different cholesterol levels and PIP2 conditions. Our results suggest that in BAEC the role of PIP2, as a mediator of membrane-cytoskeleton adhesion, is regulated by cholesterol. Our findings confirm the specific role of cholesterol in endothelial cells and may have implications for cholesterol-dependent vascular pathologies. PMID:23162471

  16. DNA Damage, DNA Repair, Aging, and Neurodegeneration.

    PubMed

    Maynard, Scott; Fang, Evandro Fei; Scheibye-Knudsen, Morten; Croteau, Deborah L; Bohr, Vilhelm A

    2015-09-18

    Aging in mammals is accompanied by a progressive atrophy of tissues and organs, and stochastic damage accumulation to the macromolecules DNA, RNA, proteins, and lipids. The sequence of the human genome represents our genetic blueprint, and accumulating evidence suggests that loss of genomic maintenance may causally contribute to aging. Distinct evidence for a role of imperfect DNA repair in aging is that several premature aging syndromes have underlying genetic DNA repair defects. Accumulation of DNA damage may be particularly prevalent in the central nervous system owing to the low DNA repair capacity in postmitotic brain tissue. It is generally believed that the cumulative effects of the deleterious changes that occur in aging, mostly after the reproductive phase, contribute to species-specific rates of aging. In addition to nuclear DNA damage contributions to aging, there is also abundant evidence for a causative link between mitochondrial DNA damage and the major phenotypes associated with aging. Understanding the mechanistic basis for the association of DNA damage and DNA repair with aging and age-related diseases, such as neurodegeneration, would give insight into contravening age-related diseases and promoting a healthy life span.

  17. Allogeneic mesenchymal stem cells restore cardiac function in chronic ischemic cardiomyopathy via trilineage differentiating capacity

    PubMed Central

    Quevedo, Henry C.; Hatzistergos, Konstantinos E.; Oskouei, Behzad N.; Feigenbaum, Gary S.; Rodriguez, Jose E.; Valdes, David; Pattany, Pradip M.; Zambrano, Juan P.; Hu, Qinghua; McNiece, Ian; Heldman, Alan W.; Hare, Joshua M.

    2009-01-01

    The mechanism(s) underlying cardiac reparative effects of bone marrow-derived mesenchymal stem cells (MSC) remain highly controversial. Here we tested the hypothesis that MSCs regenerate chronically infarcted myocardium through mechanisms comprising long-term engraftment and trilineage differentiation. Twelve weeks after myocardial infarction, female swine received catheter-based transendocardial injections of either placebo (n = 4) or male allogeneic MSCs (200 million; n = 6). Animals underwent serial cardiac magnetic resonance imaging, and in vivo cell fate was determined by co-localization of Y-chromosome (Ypos) cells with markers of cardiac, vascular muscle, and endothelial lineages. MSCs engrafted in infarct and border zones and differentiated into cardiomyocytes as ascertained by co-localization with GATA-4, Nkx2.5, and α-sarcomeric actin. In addition, Ypos MSCs exhibited vascular smooth muscle and endothelial cell differentiation, contributing to large and small vessel formation. Infarct size was reduced from 19.3 ± 1.7% to 13.9 ± 2.0% (P < 0.001), and ejection fraction (EF) increased from 35.0 ± 1.7% to 41.3 ± 2.7% (P < 0.05) in MSC but not placebo pigs over 12 weeks. This was accompanied by increases in regional contractility and myocardial blood flow (MBF), particularly in the infarct border zone. Importantly, MSC engraftment correlated with functional recovery in contractility (R = 0.85, P < 0.05) and MBF (R = 0.76, P < 0.01). Together these findings demonstrate long-term MSC survival, engraftment, and trilineage differentiation following transplantation into chronically scarred myocardium. MSCs are an adult stem cell with the capacity for cardiomyogenesis and vasculogenesis which contribute, at least in part, to their ability to repair chronically scarred myocardium. PMID:19666564

  18. [Promotion of Function of Endothelial Progenitor Cells with Shexiang Baoxin Pill Treatment under Shear Stress].

    PubMed

    Li, Gang; Chen, Yang; Wu, Jiang

    2015-08-01

    The aim of this study was to investigate whether shear stress could promote function of endothelial progenitor cells (EPCs) with Shexiang Baoxin Pill (SBP) treatment in vitro, and to study whether shear stress contributed to vascular injury repair by EPCs. EPCs were isolated and characterized; EPCs' proliferation, migration, adhesion, tube formation and eNOS protein level in vitro were investigated by culturing confluent EPCs in 4 mg/mL SBP under physiological shear stress (15 dyne/cm2) for up to 24 hours. Afterwards, EPCs were transfused into rats after wire-induced carotid artery injury augmented re-endothelialization. The results showed that, compared to the SBP group, the shear stress+SBP group obviously enhanced EPCs proliferation, migration, adhesion, tube formation and eNOS protein expression in vitro (P<0.01). After one week, immunofluorescence staining showed that endothelial regeneration rate obviously enhanced in shear stress+SBP group (P<0.01). The present study demonstrates that shear stress can promote function of endothelial progenitor cells treated with SBP, which improves the vascular injury repair potentials of EPCs. PMID:26710458

  19. Functional characterization of late outgrowth endothelial progenitor cells in patients with end-stage renal failure

    PubMed Central

    Zhao, Jing; Bolton, Eleanor M; Randle, Lucy; Bradley, John Andrew; Lever, Andrew M L

    2014-01-01

    Renal transplantation is potentially curative in renal failure, but long-term efficacy is limited by untreatable chronic rejection. Endothelial damage contributes to chronic rejection and is potentially repairable by circulating endothelial progenitor cells (EPC). The frequency and function of EPC are variably influenced by end-stage renal failure (ESRF). Here, we isolated and functionally characterized the late outgrowth EPC (LO-EPC) from ESRF patients to investigate their potential for endothelial repair. Patients with ESRF generated more LO-EPC colonies than healthy controls and had higher plasma levels of IL-1rα, IL-16, IL-6, MIF, VEGF, Prolactin, and PLGF. Patients' LO-EPC displayed normal endothelial cell morphology, increased secretion of PLGF, MCP-1, and IL-1β, and normal network formation in vitro and in vivo. They demonstrated decreased adhesion to extracellular matrix. Integrin gene profiles and protein expression were comparable in patients and healthy volunteers. In some patients, mesenchymal stem cells (MSC) were co-isolated and could be differentiated into adipocytes and osteocytes in vitro. This is the first study to characterize LO-EPC from patients with ESRF. Their behavior in vitro reflects the presence of elevated trophic factors; their ability to proliferate in vitro and angiogenic function makes them candidates for prevention of chronic rejection. Their impaired adhesion and the presence of MSC are areas for potential therapeutic intervention. PMID:24471420

  20. Innovative Flow Cytometry Allows Accurate Identification of Rare Circulating Cells Involved in Endothelial Dysfunction

    PubMed Central

    Boraldi, Federica; Bartolomeo, Angelica; De Biasi, Sara; Orlando, Stefania; Costa, Sonia; Cossarizza, Andrea; Quaglino, Daniela

    2016-01-01

    Introduction Although rare, circulating endothelial and progenitor cells could be considered as markers of endothelial damage and repair potential, possibly predicting the severity of cardiovascular manifestations. A number of studies highlighted the role of these cells in age-related diseases, including those characterized by ectopic calcification. Nevertheless, their use in clinical practice is still controversial, mainly due to difficulties in finding reproducible and accurate methods for their determination. Methods Circulating mature cells (CMC, CD45-, CD34+, CD133-) and circulating progenitor cells (CPC, CD45dim, CD34bright, CD133+) were investigated by polychromatic high-speed flow cytometry to detect the expression of endothelial (CD309+) or osteogenic (BAP+) differentiation markers in healthy subjects and in patients affected by peripheral vascular manifestations associated with ectopic calcification. Results This study shows that: 1) polychromatic flow cytometry represents a valuable tool to accurately identify rare cells; 2) the balance of CD309+ on CMC/CD309+ on CPC is altered in patients affected by peripheral vascular manifestations, suggesting the occurrence of vascular damage and low repair potential; 3) the increase of circulating cells exhibiting a shift towards an osteoblast-like phenotype (BAP+) is observed in the presence of ectopic calcification. Conclusion Differences between healthy subjects and patients with ectopic calcification indicate that this approach may be useful to better evaluate endothelial dysfunction in a clinical context. PMID:27560136

  1. Is exercise training an effective therapy targeting endothelial dysfunction and vascular wall inflammation?

    PubMed

    Ribeiro, Fernando; Alves, Alberto Jorge; Duarte, José Alberto; Oliveira, José

    2010-06-11

    There is an increasing evidence that endothelial dysfunction and vascular wall inflammation are present in all stages of atherosclerosis. Atherosclerosis does not have to necessarily progress to an acute clinical event. Several therapeutic strategies exist, such as exercise training, which mitigates endothelial dysfunction and inflammation. Exercise training consistently improves the nitric oxide bioavailability, and the number of endothelial progenitor cells, and also diminishes the level of inflammatory markers, namely pro-inflammatory cytokines and C-reactive protein. However, the mechanisms by which exercise improves endothelial function in coronary artery disease patients are not fully clarified. Several mechanisms have been proposed to explain the positive effect of exercise on the disease progression. They include the decrease in cytokine production by the adipose tissue, skeletal muscles, endothelial cells, and blood mononuclear cells, and also, the increase in the bioavailability of nitric oxide, antioxidant defences, and regenerative capacity of endothelium. This study aims to provide a critical review of the literature linking exercise, inflammation, and endothelial dysfunction in coronary artery patients, and to discuss the potential mechanisms behind the exercise-training improvement of endothelial function and inflammatory status.

  2. Activated neutrophils disrupt endothelial monolayer integrity by an oxygen radical-independent mechanism

    SciTech Connect

    Harlan, J.M.; Schwartz, B.R.; Reidy, M.A.; Schwartz, S.M.; Ochs, H.D.; Harker, L.A.

    1985-02-01

    The effect of activated neutrophils on endothelial monolayer integrity in vitro has been measured by assessing the capacity of endothelial monolayers on polycarbonate filters to exclude /sup 125/I-albumin. Although formylmethionyl-leucyl-phenylalanine (FMLP)-activated neutrophils failed to induce /sup 51/Cr-release or detachment after 4 hours of incubation with endothelial monolayers cultured in polystyrene wells, FMLP-activated neutrophils produced a marked increase in the passage of /sup 125/I-albumin across bovine aortic or pulmonary artery endothelial monolayers on polycarbonate filters. This effect was evident as early as 30 minutes following the addition of FMLP-activated neutrophils to the monolayer and reached 180% over control values at 2 hours (p . 0.001). Light and transmission electron microscopic examination of the polycarbonate filters exposed to FMLP-activated neutrophils revealed focal disruption of the endothelial monolayers. Chronic granulomatous disease neutrophils produced similar disruption of the endothelial monolayer at 2 hours. Moreover, catalase and superoxide dismutase failed to reduce significantly the neutrophil-mediated increase in /sup 125/I-albumin passage at 2 hours. Cell-free postsecretory supernatants of FMLP-activated neutrophils, leukotriene C4, and platelet activating factor did not induce a significant increase in /sup 125/I-albumin passage across the endothelial monolayers. Of note, FMLP-activated neutrophils from a patient with a congenital abnormality of neutrophil adhesion and chemotaxis did not induce disruption of the monolayer or increase /sup 125/I-albumin passage.

  3. Characterization of Postreplication Repair in Mutagen-Sensitive Strains of DROSOPHILA MELANOGASTER

    PubMed Central

    Boyd, J. B.; Setlow, R. B.

    1976-01-01

    Mutants of Drosophila melanogaster, with suspected repair deficiencies, were analyzed for their capacity to repair damage induced by X-rays and UV radiation. Analysis was performed on cell cultures derived from embryos of homozygous mutant stocks. Postreplication repair following UV radiation has been analyzed in mutant stocks derived from a total of ten complementation groups. Cultures were irradiated, pulse-labeled, and incubated in the dark prior to analysis by alkaline sucrose gradient centrifugation. Kinetics of the molecular weight increase in newly synthesized DNA were assayed after cells had been incubated in the presence or absence of caffeine. Two separate pathways of postreplication repair have been tentatively identified by mutants derived from four complementation groups. The proposed caffeine sensitive pathway (CAS) is defined by mutants which also disrupt meiosis. The second pathway (CIS) is caffeine insensitive and is not yet associated with meiotic functions. All mutants deficient in postreplication repair are also sensitive to nitrogen mustard. The mutants investigated display a normal capacity to repair single-strand breaks induced in DNA by X-rays, although two may possess a reduced capacity to repair damage caused by localized incorporation of high specific activity thymidine-3H. The data have been employed to construct a model for repair of UV-induced damage in Drosophila DNA. Implications of the model for DNA repair in mammals are discussed. PMID:826451

  4. Activation of small ruminant aortic endothelial cells after in vitro infection by caprine arthritis encephalitis virus.

    PubMed

    Jan, C L; Greenland, T; Gounel, F; Balleydier, S; Mornex, J F

    2000-12-01

    Small ruminants infected by the lentiviruses caprine arthritis-encephalitis virus (CAEV), originally isolated from a goat, or maedi-visna virus, originally from sheep, typically develop an organising lymphoid infiltration of affected tissues. This could reflect modulation of the migration pattern of lymphocytes in infected animals. Possible active contribution by vascular endothelial cells was investigated using an in vitro model. Low-passage cultured ovine aortic endothelium proved susceptible to productive infection by CAEV without significant cytotoxicity. Infected endothelial cells maintained expression of endothelial markers, increased MHC class I antigen expression and initiated expression of the adhesion molecule VCAM -1 and, at a late stage, MHC class II antigens. Infected endothelial cells showed a two-fold increase in binding capacity for sheep peripheral blood leucocytes over uninfected controls. Such events could contribute to the tissue distribution of lymphoid cells and local immune responses in lentiviral infections of small ruminants. PMID:11124093

  5. Regulation of endothelial permeability by second messengers.

    PubMed

    Siflinger-Birnboim, A; Malik, A B

    1996-02-01

    The mechanisms by which mediators such as oxidants released by neutrophil (PMN) activation increase endothelial permeability are poorly understood. The focus of this article is to identify some of these mechanisms. Studies using endothelial cell monolayers in culture have shown that PMN activation increases endothelial permeability both in the presence and absence of PMN-endothelial monolayer contact. Hydrogen peroxide (H2O2), an oxidant released by PMN activation, plays an important role in PMN-induced increases in endothelial permeability. The results of these studies suggest that, as with other mediators of inflammation (e.g., histamine, thrombin) the mechanism of H2O2-induced increase in endothelial permeability involves activation of endothelial protein kinase C (PKC) and increase in endothelial cytosolic Ca2+.

  6. The Secretome of Endothelial Progenitor Cells Promotes Brain Endothelial Cell Activity through PI3-Kinase and MAP-Kinase

    PubMed Central

    Di Santo, Stefano; Seiler, Stefanie; Fuchs, Anna-Lena; Staudigl, Jennifer; Widmer, Hans Rudolf

    2014-01-01

    Background Angiogenesis and vascular remodelling are crucial events in tissue repair mechanisms promoted by cell transplantation. Current evidence underscores the importance of the soluble factors secreted by stem cells in tissue regeneration. In the present study we investigated the effects of paracrine factors derived from cultured endothelial progenitor cells (EPC) on rat brain endothelial cell properties and addressed the signaling pathways involved. Methods Endothelial cells derived from rat brain (rBCEC4) were incubated with EPC-derived conditioned medium (EPC-CM). The angiogenic response of rBCEC4 to EPC-CM was assessed as effect on cell number, migration and tubular network formation. In addition, we have compared the outcome of the in vitro experiments with the effects on capillary sprouting from rat aortic rings. The specific PI3K/AKT inhibitor LY294002 and the MEK/ERK inhibitor PD98059 were used to study the involvement of these two signaling pathways in the transduction of the angiogenic effects of EPC-CM. Results Viable cell number, migration and tubule network formation were significantly augmented upon incubation with EPC-CM. Similar findings were observed for aortic ring outgrowth with significantly longer sprouts. The EPC-CM-induced activities were significantly reduced by the blockage of the PI3K/AKT and MEK/ERK signaling pathways. Similarly to the outcome of the rBCEC4 experiments, inhibition of the PI3K/AKT and MEK/ERK pathways significantly interfered with capillary sprouting induced by EPC-CM. Conclusion The present study demonstrates that EPC-derived paracrine factors substantially promote the angiogenic response of brain microvascular endothelial cells. In addition, our findings identified the PI3K/AKT and MEK/ERK pathways to play a central role in mediating these effects. PMID:24755675

  7. Rescheduling with iterative repair

    NASA Technical Reports Server (NTRS)

    Zweben, Monte; Davis, Eugene; Daun, Brian; Deale, Michael

    1992-01-01

    This paper presents a new approach to rescheduling called constraint-based iterative repair. This approach gives our system the ability to satisfy domain constraints, address optimization concerns, minimize perturbation to the original schedule, produce modified schedules, quickly, and exhibits 'anytime' behavior. The system begins with an initial, flawed schedule and then iteratively repairs constraint violations until a conflict-free schedule is produced. In an empirical demonstration, we vary the importance of minimizing perturbation and report how fast the system is able to resolve conflicts in a given time bound. We also show the anytime characteristics of the system. These experiments were performed within the domain of Space Shuttle ground processing.

  8. The role of pleiotrophin in bone repair.

    PubMed

    Lamprou, Margarita; Kaspiris, Angelos; Panagiotopoulos, Elias; Giannoudis, Peter V; Papadimitriou, Evangelia

    2014-12-01

    Bone has an enormous capacity for growth, regeneration, and remodelling, largely due to induction of osteoblasts that are recruited to the site of bone formation. Although the pathways involved have not been fully elucidated, it is well accepted that the immediate environment of the cells is likely to play a role via cell–matrix interactions, mediated by several growth factors. Formation of new blood vessels is also significant and interdependent to bone formation, suggesting that enhancement of angiogenesis could be beneficial during the process of bone repair. Pleiotrophin (PTN), also called osteoblast-specific factor 1, is a heparin-binding angiogenic growth factor, with a well-defined and significant role in both physiological and pathological angiogenesis. In this review we summarise the existing evidence on the role of PTN in bone repair.

  9. Endothelial Caveolar Subcellular Domain Regulation of Endothelial Nitric Oxide Synthase

    PubMed Central

    Ramadoss, Jayanth; Pastore, Mayra B.; Magness, Ronald R.

    2015-01-01

    SUMMARY Complex regulatory processes alter the activity of endothelial nitric oxide synthase (eNOS) leading to nitric oxide (NO) production by endothelial cells under various physiological states. These complex processes require specific sub-cellular eNOS partitioning between plasma membrane caveolar domains and non-caveolar compartments.eNOS translocation from the plasma membrane to intracellular compartments is important for eNOS activation and subsequent NO biosynthesis. We present data reviewing and interpreting information: 1) the coupling of endothelial plasma membrane receptor systems in the caveolar structure relative to eNOS trafficking; 2) how eNOS trafficking relates to specific protein-protein interaction for inactivation and activation of eNOS; and 3) how these complex mechanisms confer specific subcellular location relative to eNOS multi-site phosphorylation and signaling.Dysfunction in regulation of eNOS activation may contribute to several disease states; in particular gestational endothelial abnormalities (preeclampsia, gestational diabetes, etc) that have life-long deleterious health consequences that predispose the offspring to develop hypertensive disease, type II diabetes and adiposity.1 PMID:23745825

  10. Regulation of endothelial proliferation by the renin-angiotensin system in human umbilical vein endothelial cells.

    PubMed

    Herr, D; Rodewald, M; Fraser, H M; Hack, G; Konrad, R; Kreienberg, R; Wulff, C

    2008-07-01

    This study was performed in order to evaluate the role of angiotensin II in physiological angiogenesis. Human umbilical vein endothelial cells (HUVEC) were stained for angiotensin II type 1 receptor (AGTR1) immunocytochemically and for gene expression of renin-angiotensin system (RAS) components. The regulation of the angiogenesis-associated genes vascular endothelial growth factor (VEGF) and angiopoietins (ANGPT1 and ANGPT2) were studied using quantitative RT-PCR. Furthermore, we examined the effect of angiotensin II on the proliferation of HUVEC using Ki-67 as well as BrdU immunocytochemistry and investigated whether the administration of the AGTR1 blocker candesartan or the VEGF antagonist FLT1-Fc could suppress the observed angiotensin II-dependent proangiogenic effect. AGTR1 was expressed in HUVEC and the administration of angiotensin II significantly increased the gene expression of VEGF and decreased the gene expression of ANGPT1. Since the expression of ANGPT2 was not affected significantly the ratio of ANGPT1/ANGPT2 was decreased. In addition, a significantly increased endothelial cell proliferation was observed after stimulation with angiotensin II, which was suppressed by the simultaneous administration of candesartan or the VEGF antagonist FLT1-Fc. These results indicate the potential capacity of angiotensin II in influencing angiogenesis by the regulation of angiogenesis-associated genes via AGTR1. Since VEGF blockade opposed the effect of angiotensin II on cell proliferation, it is hypothesised that VEGF mediates the angiotensin II-dependent effect in concert with the changes in angiopoietin expression. This is the first report of the RAS on the regulation of angiogenesis-associated genes in physiology.

  11. Instructive role of the vascular niche in promoting tumour growth and tissue repair by angiocrine factors

    PubMed Central

    Butler, Jason M.; Kobayashi, Hideki; Rafii, Shahin

    2010-01-01

    The precise mechanisms whereby anti-angiogenesis therapy blocks tumour growth or causes vascular toxicity are unknown. We propose that endothelial cells establish a vascular niche that promotes tumour growth and tissue repair not only by delivering nutrients and O2 but also through an ‘angiocrine’ mechanism by producing stem and progenitor cell-active trophogens. Identification of endothelial-derived instructive angiocrine factors will allow direct tumour targeting, while diminishing the unwanted side effects associated with the use of anti-angiogenic agents. PMID:20094048

  12. DNA Repair Alterations in Children With Pediatric Malignancies: Novel Opportunities to Identify Patients at Risk for High-Grade Toxicities

    SciTech Connect

    Ruebe, Claudia E.

    2010-10-01

    Purpose: To evaluate, in a pilot study, the phosphorylated H2AX ({gamma}H2AX) foci approach for identifying patients with double-strand break (DSB) repair deficiencies, who may overreact to DNA-damaging cancer therapy. Methods and Materials: The DSB repair capacity of children with solid cancers was analyzed compared with that of age-matched control children and correlated with treatment-related normal-tissue responses (n = 47). Double-strand break repair was investigated by counting {gamma}H2AX foci in blood lymphocytes at defined time points after irradiation of blood samples. Results: Whereas all healthy control children exhibited proficient DSB repair, 3 children with tumors revealed clearly impaired DSB repair capacities, and 2 of these repair-deficient children developed life-threatening or even lethal normal-tissue toxicities. The underlying mutations affecting regulatory factors involved in DNA repair pathways were identified. Moreover, significant differences in mean DSB repair capacity were observed between children with tumors and control children, suggesting that childhood cancer is based on genetic alterations affecting DSB repair function. Conclusions: Double-strand break repair alteration in children may predispose to cancer formation and may affect children's susceptibility to normal-tissue toxicities. Phosphorylated H2AX analysis of blood samples allows one to detect DSB repair deficiencies and thus enables identification of children at risk for high-grade toxicities.

  13. Postpartum cervical repair in mice: a morphological characterization and potential role for angiogenic factors.

    PubMed

    Stanley, Robert; Ohashi, Takako; Mowa, Chishimba

    2015-10-01

    The cervix undergoes marked mechanical trauma during delivery of the baby at birth. As such, a timely and complete tissue repair postpartum is necessary to prevent obstetrical complications, such as cervicitis, ectropion, hemorrhage, repeated miscarriages or abortions and possibly preterm labor and malignancies. However, our knowledge of normal cervical repair is currently incomplete and factors that influence repair are unclear. Here, we characterize the morphological and angiogenic profile of postpartum repair in mice cervix during the first 48 h of postpartum. The key findings presented here are: (1) cervical epithelial folds and size are diminished during the first 48 h of postpartum repair, (2) hypoxic inducible factor 1a, vascular endothelial growth factor (VEGF), and VEGF receptor 1 expression are pronounced early in postpartum cervical repair, and (3) VEGF receptor 2 gene and protein expressions are variable. We conclude that postpartum cervical repair involves gross and microscopic changes and is linked to expression of angiogenic factors. Future studies will assess the suitability of these factors, identified in the present study, as potential markers for determining the phase of postpartum cervical repair in obstetrical complications, such as cervical lacerations.

  14. Isolation of endothelial cells and pericytes from swine corpus luteum.

    PubMed

    Basini, G; Falasconi, I; Bussolati, S; Grolli, S; Ramoni, R; Grasselli, F

    2014-07-01

    From an angiogenesis perspective, the ovary offers a unique opportunity to study the physiological development of blood vessels. The first purpose of this work was to set up a protocol for the isolation of pig corpus luteum endothelial cells, which were characterized by both morphologic parameters and the expression of typical molecular markers; we also verified their ability to form capillary-like structures in a 3-dimensional matrix, their response to hypoxia and their migration in the presence of vascular endothelial growth factor (VEGF). The effectiveness of our isolation protocol was confirmed by the characteristic "cobblestone shape" of isolated cells at confluence as well as their expression of all the examined endothelial markers. Our data also showed a significant cell production of VEGF and nitric oxide. Isolated endothelial cells were also responsive to hypoxia by increasing the expression and production of VEGF and decreasing that of nitric oxide. In the angiogenesis bioassay, cells displayed the ability of forming capillary-like structures and also exhibited a significant migration in the scratch test. Our data suggest that the isolation of luteal endothelial cells represents a promising tool in experiments designed to clarify the biology of the angiogenic process. Furthermore, we have demonstrated that the isolated population comprises a subset of cells with a multidifferentiative capacity toward the chondrocytic and adipocytic phenotypes. These data suggest the presence of a perivascular or adventitial cell niche in the vascular wall of the corpus luteum populated with cells showing mesenchymal stem cell-like features, as already demonstrated for the adipose tissue and endometrium.

  15. Symposium overview: genetic polymorphisms in DNA repair and cancer risk.

    PubMed

    Hu, J J; Mohrenweiser, H W; Bell, D A; Leadon, S A; Miller, M S

    2002-11-15

    A symposium, Genetic Polymorphisms in DNA Repair and Cancer Risk, was presented at the 40th Annual Meeting of the Society of Toxicology, held in San Francisco, California, in March 2001. A brief report of the symposium was published (Kaiser, Science 292, 837-838, 2001). Molecular epidemiological studies have shown that polymorphic variants of genes involved in the metabolism and repair of carcinogens can act as cancer susceptibility genes. These variants of drug metabolic and DNA-repair enzymes either increase the activation of chemical carcinogens or decrease the cells' ability to detoxify/repair mutagenic damages. Although on an individual basis these variant alleles may only slightly change catalytic activity and increase cancer risk, their polymorphic frequency in the human population may contribute to a high proportion of cancer cases. Studies conducted over the past few years have identified variant alleles for a number of DNA-repair genes, some of which have been shown to change DNA-repair capacity. Identifying these genotypic alterations in DNA-repair enzymes and their association with cancer may help to elucidate the mechanisms of cancer etiology and to predict both disease risk and response to cancer therapy, since most antineoplastic treatments mediate their effects through DNA damage.

  16. DNA repair in murine embryonic stem cells and differentiated cells

    SciTech Connect

    Tichy, Elisia D. Stambrook, Peter J.

    2008-06-10

    Embryonic stem (ES) cells are rapidly proliferating, self-renewing cells that have the capacity to differentiate into all three germ layers to form the embryo proper. Since these cells are critical for embryo formation, they must have robust prophylactic mechanisms to ensure that their genomic integrity is preserved. Indeed, several studies have suggested that ES cells are hypersensitive to DNA damaging agents and readily undergo apoptosis to eliminate damaged cells from the population. Other evidence suggests that DNA damage can cause premature differentiation in these cells. Several laboratories have also begun to investigate the role of DNA repair in the maintenance of ES cell genomic integrity. It does appear that ES cells differ in their capacity to repair damaged DNA compared to differentiated cells. This minireview focuses on repair mechanisms ES cells may use to help preserve genomic integrity and compares available data regarding these mechanisms with those utilized by differentiated cells.

  17. [Physical activity and endothelial dysfunction in type 2 diabetic patients: the role of nitric oxide and oxidative stress].

    PubMed

    Brinkmann, Christian; Schwinger, Robert H G; Brixius, Klara

    2011-06-01

    Type 2 diabetic patients have an increased level of systemic free radicals, which severely restrict the bioavailability of endothelium-derived nitric oxide (NO) and thus contribute to the development of an endothelial dysfunction. This review analyses the influence of physical training on molecular development mechanisms of the endothelial dysfunction and determines the significance of regular physical exercise for the endothelial function in type 2 diabetic patients. Systematic training reinforces the endogenic antioxidative capacity and results in a reduction in oxidative stress. Training - also combined with a change in diet - furthermore reduces hyperglycaemic blood sugar levels, thus curbing a major source of free radicals in diabetes. Moreover, physical exercise enhances vascular NO synthesis through an increased availability/activity of endothelial NO synthases (eNOS). Endurance, as well as resistance training with submaximal intensity or a combination of both forms of training is suitable to effectively improve the endothelial function in type 2 diabetic patients in the long term. PMID:21360292

  18. Bone fracture repair - series (image)

    MedlinePlus

    The three main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a surgery to repair the fracture-frequently, metal rods, screws or plates are used to repair the ...

  19. Cleft lip and palate repair

    MedlinePlus

    Orofacial cleft; Craniofacial birth defect repair; Cheiloplasty; Cleft rhinoplasty; Palatoplasty; Tip rhinoplasty ... these conditions at birth. Most times, cleft lip repair is done when the child is 6 to ...

  20. Electric motor model repair specifications

    SciTech Connect

    1995-08-01

    These model repair specifications list the minimum requirements for repair and overhaul of polyphase AC squireel cage induction motors. All power ranges, voltages, and speeds of squirrel cage motors are covered.

  1. Restoring stem cell mobilization to promote vascular repair in diabetes.

    PubMed

    Albiero, Mattia; Avogaro, Angelo; Fadini, Gian Paolo

    2013-04-01

    Diabetes triggers endothelial dysfunction, which is linked to increased risk of cardiovascular diseases. Stem and progenitor cells from the bone marrow are involved in the maintenance of vascular integrity. Diabetic patients show a dysfunction of these cells, which might represent a novel pathophysiological mechanism of vascular disease. Specifically, stem and progenitor cells fail to egress from the bone marrow (BM) due to BM pathological alterations and unresponsiveness to mobilizing stimuli. In this review, we describe impaired stem cell mobilization in diabetes as a mechanism of failed vascular repair and we provide evidence that pharmacological strategies can restore mobilization. We discuss recent advances in the knowledge of aberrant organization of the diabetic BM and its implications for impaired mobilization. Finally, we describe in detail the pharmacological exploitation of the G-CSF/DPP-4(CD26)/SDF-1α axis as a novel strategy to improve mobilization and attain vascular repair in diabetes.

  2. Preserved function of late outgrowth endothelial cells in medically-treated hypertensive patients under well-controlled conditions

    PubMed Central

    Chen, Zhi; Herrmann, Sandra M. S.; Zhu, Xiangyang; Jordan, Kyra L.; Gloviczki, Monika L.; Lerman, Amir; Textor, Stephen C.; Lerman, Lilach O.

    2014-01-01

    Endothelial-progenitor-cells participate in renal repair, but their number and function may be impaired by exposure to cardiovascular risk factors. The number of circulating endothelial-progenitor-cells is decreased in essential and renovascular hypertensive patients, but the effects of hypertension on endothelial-progenitor-cell function are incompletely understood. We hypothesized that endothelial-progenitor-cell function was preserved under well-controlled conditions in treated hypertensive patients. Patients with atherosclerotic-renal-artery-stenosis (n=22) or essential-hypertension (n=24) were studied during controlled sodium intake and anti-hypertensive regimen. Late-outgrowth-endothelial-progenitor-cells were isolated from the inferior vena cava and renal vein blood of atherosclerotic-renal-artery-stenosis and essential-hypertension patients, and a peripheral vein of matched normotensive controls (n=18). The angiogenic function of endothelial-progenitor-cells was assessed in vitro and multi-detector computer tomography used to measure single-kidney hemodynamics and function in atherosclerotic-renal-artery-stenosis and essential-hypertension patients. Inflammatory biomarkers and endothelial-progenitor-cell homing signals levels and renal release were calculated. Inferior vena cava and renal vein-obtained endothelial-progenitor-cell function were similar in atherosclerotic-renal-artery-stenosis and essential-hypertension patients, and comparable to that in normal controls (tube length 171.86±16.846, 191.09±14.222, 174.925±19.774μm, respectively). Function of renal vein-obtained endothelial-progenitor-cells directly correlated with stenotic-kidney glomerular filtration rate, endothelial-progenitor-cell homing factors and anti-inflammatory mediator levels in atherosclerotic-renal-artery-stenosis patients. Therefore, endothelial-progenitor-cell function was relatively preserved in atherosclerotic-renal-artery-stenosis patients, although it directly correlated

  3. Radioligand binding to muscarinic receptors of bovine aortic endothelial cells.

    PubMed

    Brunner, F; Kukovetz, W R

    1991-02-01

    1. Muscarinic receptors on endothelial cells of bovine thoracic aorta were characterized by binding assays in which (-)-[3H]-N-methyl quinuclidinyl benzilate ([3H]-NMeQNB) was used as radioligand. 2. Binding of [3H]-NMeQNB to crude membranes of freshly isolated endothelial cells was atropine-displaceable and of high affinity (KD = 0.48 nM) to a single class of sites (maximum binding capacity: 14 +/- 3 fmol mg-1 protein). Stereospecificity of the binding sites was demonstrated in experiments in which [3H]-NMeQNB binding was inhibited by dexetimide in the nanomolar range (KI = 0.63 nM) and by levetimide, its stereoisomer in the micromolar range (KI = 3.2 microM) (selectivity factor: approximately 5000). 3. Drug competition curves indicated a single class of binding sites for antagonists and the following apparent affinities (KI, nM): methyl atropine: 1.1: 4-diphenylacetoxy N-methyl piperidine methyl bromide (4-DAMP): 3.4; pirenzepine: 16; 11-[2-diethylamino-methyl)-1-piperidinyl- acetyl]-5,11-dihydro-6H-pyrido(2,3-b)1,4-benzodiazepine-6-one (AF-DX 116); 2.500. Competition of acetylcholine with [3H]-NMeQNB was best described by two affinity sites (or states) (KH = 0.82 microM, KL = 1.6 microM). In the presence of guanylimido diphosphate [Gpp(NH)p] (100 microM), acetylcholine affinity (IC50) was slightly, but significantly reduced (factor approximately 4). 4. Binding of [3H]-NMeQNB to freshly harvested intact cells was also atropine-displaceable, stereospecific (selectivity factor: approximately 3500) and of high affinity (KD = 0.35 nM). The maximum binding capacity (9 +/- 2 fmol mg-1 total cell protein) was comparable to that of membranes and corresponded to approximately 900 binding sites per endothelial cell. Binding to enzymatically harvested and cultured endothelial cells, or membranes derived therefrom, showed no atropine-displaceable binding. 5. The results suggest that (1) bovine aortic endothelial cells contain muscarinic binding sites with all necessary

  4. Instruction of Circulating Endothelial Progenitors In Vitro towards Specialized Blood-Brain Barrier and Arterial Phenotypes

    PubMed Central

    Ponio, Julie Boyer-Di; El-Ayoubi, Fida; Glacial, Fabienne; Ganeshamoorthy, Kayathiri; Driancourt, Catherine; Godet, Maeva; Perrière, Nicolas; Guillevic, Oriane; Couraud, Pierre Olivier; Uzan, Georges

    2014-01-01

    Objective The vascular system is adapted to specific functions in different tissues and organs. Vascular endothelial cells are important elements of this adaptation, leading to the concept of ‘specialized endothelial cells’. The phenotype of these cells is highly dependent on their specific microenvironment and when isolated and cultured, they lose their specific features after few passages, making models using such cells poorly predictive and irreproducible. We propose a new source of specialized endothelial cells based on cord blood circulating endothelial progenitors (EPCs). As prototype examples, we evaluated the capacity of EPCs to acquire properties characteristic of cerebral microvascular endothelial cells (blood-brain barrier (BBB)) or of arterial endothelial cells, in specific inducing culture conditions. Approach and Results First, we demonstrated that EPC-derived endothelial cells (EPDCs) co-cultured with astrocytes acquired several BBB phenotypic characteristics, such as restricted paracellular diffusion of hydrophilic solutes and the expression of tight junction proteins. Second, we observed that culture of the same EPDCs in a high concentration of VEGF resulted, through activation of Notch signaling, in an increase of expression of most arterial endothelial markers. Conclusions We have thus demonstrated that in vitro culture of early passage human cord blood EPDCs under specific conditions can induce phenotypic changes towards BBB or arterial phenotypes, indicating that these EPDCs maintain enough plasticity to acquire characteristics of a variety of specialized phenotypes. We propose that this property of EPDCs might be exploited for producing specialized endothelial cells in culture to be used for drug testing and predictive in vitro assays. PMID:24392113

  5. In vitro differentiation of porcine aortic vascular precursor cells to endothelial and vascular smooth muscle cells.

    PubMed

    Zaniboni, Andrea; Bernardini, Chiara; Bertocchi, Martina; Zannoni, Augusta; Bianchi, Francesca; Avallone, Giancarlo; Mangano, Chiara; Sarli, Giuseppe; Calzà, Laura; Bacci, Maria Laura; Forni, Monica

    2015-09-01

    Recent findings suggest that progenitor and multipotent mesenchymal stromal cells (MSCs) are associated with vascular niches. Cells displaying mesenchymal properties and differentiating to whole components of a functional blood vessel, including endothelial and smooth muscle cells, can be defined as vascular stem cells (VSCs). Recently, we isolated a population of porcine aortic vascular precursor cells (pAVPCs), which have MSC- and pericyte-like properties. The aim of the present work was to investigate whether pAVPCs possess VSC-like properties and assess their differentiation potential toward endothelial and smooth muscle lineages. pAVPCs, maintained in a specific pericyte growth medium, were cultured in high-glucose DMEM + 10% FBS (long-term medium, LTM) or in human endothelial serum-free medium + 5% FBS and 50 ng/ml of hVEGF (endothelial differentiation medium, EDM). After 21 days of culture in LTM, pAVPCs showed an elongated fibroblast-like morphology, and they seem to organize in cord-like structures. qPCR analysis of smooth muscle markers [α-smooth muscle actin (α-SMA), calponin, and smooth muscle myosin (SMM) heavy chain] showed a significant increment of the transcripts, and immunofluorescence analysis confirmed the presence of α-SMA and SMM proteins. After 21 days of culture in EDM, pAVPCs displayed an endothelial cell-like morphology and revealed the upregulation of the expression of endothelial markers (CD31, vascular endothelial-cadherin, von Willebrand factor, and endothelial nitric oxide synthase) showing the CD31-typical pattern. In conclusion, pAVPCs could be defined as a VSC-like population considering that, if they are maintained in a specific pericyte medium, they express MSC markers, and they have, in addition to the classical mesenchymal trilineage differentiation potential, the capacity to differentiate in vitro toward the smooth muscle and the endothelial cell phenotypes.

  6. Impaired endothelial proliferation and mesenchymal transition contribute to vascular rarefaction following acute kidney injury.

    PubMed

    Basile, David P; Friedrich, Jessica L; Spahic, Jasmina; Knipe, Nicole; Mang, Henry; Leonard, Ellen C; Changizi-Ashtiyani, Saeed; Bacallao, Robert L; Molitoris, Bruce A; Sutton, Timothy A

    2011-03-01

    Acute kidney injury induces the loss of renal microvessels, but the fate of endothelial cells and the mechanism of potential vascular endothelial growth factor (VEGF)-mediated protection is unknown. Cumulative cell proliferation was analyzed in the kidney of Sprague-Dawley rats following ischemia-reperfusion (I/R) injury by repetitive administration of BrdU (twice daily) and colocalization in endothelial cells with CD31 or cablin. Proliferating endothelial cells were undetectable for up to 2 days following I/R and accounted for only ∼1% of BrdU-positive cells after 7 days. VEGF-121 preserved vascular loss following I/R but did not affect proliferation of endothelial, perivascular cells or tubular cells. Endothelial mesenchymal transition states were identified by localizing endothelial markers (CD31, cablin, or infused tomato lectin) with the fibroblast marker S100A4. Such structures were prominent within 6 h and sustained for at least 7 days following I/R. A Tie-2-cre transgenic crossed with a yellow fluorescent protein (YFP) reporter mouse was used to trace the fate of endothelial cells and demonstrated interstititial expansion of YFP-positive cells colocalizing with S100A4 and smooth muscle actin following I/R. The interstitial expansion of YFP cells was attenuated by VEGF-121. Multiphoton imaging of transgenic mice revealed the alteration of YFP-positive vascular cells associated with blood vessels characterized by limited perfusion in vivo. Taken together, these data indicate that vascular dropout post-AKI results from endothelial phenotypic transition combined with an impaired regenerative capacity, which may contribute to progressive chronic kidney disease. PMID:21123492

  7. Repair of proboscis lateralis.

    PubMed

    Uğurlu, Kemal; Karşidag, Semra; Ozçelik, Derya; Sadikoğlu, Buğra; Baş, Lütfü

    2005-01-01

    We report an 8-year-old girl presented with a proboscis on the right nasal nostril, right heminasal hypoplasia, hypertelorism, and cleft lip and palate on the other side. After repair of the cleft lip and palate and the hypertelorism, we successfully reconstructed the heminose with a V-Y advancement flap containing the proboscis tube. PMID:16019753

  8. Repairing cracked glass

    NASA Technical Reports Server (NTRS)

    Helman, D. D.; Holt, J. W.; Smiser, L. V.

    1979-01-01

    Filing procedure consisting of machined lightweight fused-silica tiles coated with thin-layer of borosilicate glass produces homogeneous seal in thin glass. Procedure is useful in repairing glass envelopes, X-ray tub windows, Dewar flasks, and similar thin glass objects.

  9. Automotive Body Repair Competencies.

    ERIC Educational Resources Information Center

    D'Armond, Jack; And Others

    Designed to provide a model curriculum and guidelines, this manual presents tasks that were identified by employers, employees, and teachers as important in a postsecondary auto body repair curriculum. The tasks are divided into ten major component areas of instruction: metalworking and fiberglass, painting, frame and suspension, glass and trim,…

  10. Patent urachus repair - slideshow

    MedlinePlus

    ... Drugs & Supplements Videos & Tools About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Patent urachus repair - series—Normal anatomy URL of this ...

  11. Aircraft Propeller Hub Repair

    SciTech Connect

    Muth, Thomas R.; Peter, William H.

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  12. Basic Book Repair Methods.

    ERIC Educational Resources Information Center

    Schechter, Abraham A.

    This book addresses some common preservation techniques that invariably become necessary in library and archival collections of any size. The procedures are described in chronological sequence, and photographs show the techniques from the viewpoint of the person actually doing the work. The recommended repair methods can be accomplished using…

  13. Comprehensive Small Engine Repair.

    ERIC Educational Resources Information Center

    Hires, Bill; And Others

    This curriculum guide contains the basic information needed to repair all two- and four-stroke cycle engines. The curriculum covers four areas, each consisting of one or more units of instruction that include performance objectives, suggested activities for teacher and students, information sheets, assignment sheets, job sheets, visual aids,…

  14. Targeting Nuclear Envelope Repair.

    PubMed

    2016-06-01

    Migrating cancer cells undergo repeated rupture of the protective nuclear envelope as they squeeze through small spaces in the surrounding tissue, compromising genomic integrity. Inhibiting both general DNA repair and the mechanism that seals these tears may enhance cell death and curb metastasis. PMID:27130435

  15. Tat-APE1/ref-1 protein inhibits TNF-alpha-induced endothelial cell activation.

    PubMed

    Song, Yun Jeong; Lee, Ji Young; Joo, Hee Kyoung; Kim, Hyo Shin; Lee, Sang Ki; Lee, Kwon Ho; Cho, Chung-Hyun; Park, Jin Bong; Jeon, Byeong Hwa

    2008-03-28

    Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/ref-1) is a multifunctional protein involved both in DNA base excision repair and redox regulation. In this study we evaluated the protective role of Tat-mediated APE1/ref-1 transduction on the tumor necrosis factor (TNF)-alpha-activated endothelial activation in cultured human umbilical vein endothelial cells. To construct Tat-APE1/ref-1 fusion protein, human full length of APE1/ref-1 was fused with Tat-protein transduction domain. Purified Tat-APE1/ref-1 fusion protein efficiently transduced cultured endothelial cells in a dose-dependent manner and reached maximum expression at 1h after incubation. Transduced Tat-APE1/ref-1 showed inhibitory activity on the TNF-alpha-induced monocyte adhesion and vascular cell adhesion molecule-1 expression in cultured endothelial cells. These results suggest Tat-APE1/ref-1 might be useful to reduce vascular endothelial activation or vascular inflammatory disorders.

  16. Tailoring Material Properties of Cardiac Matrix Hydrogels to Induce Endothelial Differentiation of Human Mesenchymal Stem Cells

    PubMed Central

    Jeffords, Megan E.; Wu, Jinglei; Shah, Mickey; Hong, Yi; Zhang, Ge

    2015-01-01

    Cardiac matrix hydrogel has shown great promise as an injectable biomaterial due to the possession of cardiac-specific extracellular matrix composition. A cardiac matrix hydrogel facilitating neovascularization will further improve its therapeutic outcomes in cardiac repair. In this study, we explored the feasibility of tailoring material properties of cardiac matrix hydrogels using a natural compound, genipin, to promote endothelial differentiation of stem cells. Our results demonstrated that the genipin crosslinking could increase the mechanical properties of the cardiac matrix hydrogel to a stiffness range promoting endothelial differentiation of human mesenchymal stem cells (hMSCs). It also decreased the swelling ratio and prolonged degradation without altering gelation time. Human mesenchymal stem cells cultured on the genipin crosslinked cardiac matrix hydrogels showed great viability. After 1-day culture, hMSCs demonstrated down-regulation of early endothelial marker expression and up-regulation of mature endothelial marker expression. Especially for 1 mM genipin crosslinked cardiac matrix hydrogels, hMSCs showed particularly significant expression of mature endothelial cell marker vWF. These attractive results indicate the potential of using genipin crosslinked cardiac matrix hydrogels to promote rapid vascularization for cardiac infarction treatment through minimally invasive therapy. PMID:25946697

  17. Binding of recombinant annexin V to endothelial cells: effect of annexin V binding on endothelial-cell-mediated thrombin formation.

    PubMed Central

    van Heerde, W L; Poort, S; van 't Veer, C; Reutelingsperger, C P; de Groot, P G

    1994-01-01

    Annexin V binds with high affinity to procoagulant phospholipid vesicles and thereby inhibits the procoagulant reactions catalysed by these surfaces in vitro. In vivo, vascular endothelial cells are known to catalyse the formation of thrombin by the expression of binding sites at which procoagulant complexes can assemble. Here, we have studied the binding capacity of recombinant annexin V (rANV) to quiescent, phorbol 12-myristate 13-acetate (PMA)- and tumour necrosis factor alpha (TNF-alpha)-stimulated cultured human umbilical-vein endothelial cells (HUVEC). The dissociation constant (Kd) was 15.5 +/- 3.3 nM and the number of binding sites was 8.8 (+/- 3.9) x 10(6)/cell. These binding parameters did not change significantly during a 30 h incubation period with PMA or TNF-alpha. rANV inhibited HUVEC-mediated factor Xa formation via the extrinsic as well as the intrinsic route. Activation of factor X by the tissue factor-factor VII-factor X complex and tenase complex was inhibited with IC50 values of 43 +/- 30 nM and 33 +/- 24 nM respectively. Endothelial-cell-mediated generation of thrombin by the prothrombinase complex was inhibited by rANV with an IC50 of 16 +/- 12 nM. Preincubation of rANV with the endothelial cells did not significantly influence the IC50 values. These results show that rANV binds to the same extent to quiescent, PMA- and TNF-stimulated HUVEC, and, as a result of this binding, rANV efficiently inhibits endothelial-cell-mediated thrombin formation. PMID:8068019

  18. Repairing Holes in Pressure Walls

    NASA Technical Reports Server (NTRS)

    Mori, Paul Bruce Y.; Capriloa, Laurie J.; Corocado, Alexander R.; Gibbins, Martin N.; Horne, Robert B.

    1987-01-01

    Patches and easy-to-use tools yield pressure-tight seal. Repairer lifts patch from repair kit with hook-and-pile-tipped tool and positions it over puncture hole. With tool, even gloved repairer easily manipulates patch without damaging it.

  19. Lawn and Garden Equipment Repair.

    ERIC Educational Resources Information Center

    Hardway, Jack; And Others

    This publication is designed to supplement the Comprehensive Small Engine Rapair guide by covering in detail all aspects of lawn and garden equipment repair not included in general engine repair or the repair of other small engines. It consists of instructional materials for both teachers and students, written in terms of student performance using…

  20. Cleft lip repair - series (image)

    MedlinePlus

    ... the middle of the upper lip. A cleft palate is an opening in the roof of the mouth (palate). ... Cleft lip repair and cleft palate repair are indicated for: Repair of physical deformity Nursing, feeding, or speech problems resulting from cleft lip or palate

  1. Automotive Engine Maintenance and Repair.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide students with an understanding of automotive engine maintenance and repair. The course contains six study units covering automotive engine maintenance and repair; design classification; engine malfunction, diagnosis, and repair; engine disassembly; engine…

  2. Analysis of Endothelial Barrier Function In Vitro

    PubMed Central

    Wang, Yuping; Alexander, J. Steven

    2016-01-01

    Increased microvascular solute permeability underlies many forms of pathophysiological conditions, including inflammation. Endothelial monolayer cultures provide an excellent model system which allows systemic and mechanistic study of endothelial barrier function and paracellular permeability in vitro. The endothelial-specific complexus adherens junction protein VE-cadherin and their intracellular complex form pericellular structures along the cell borders which are critical to regulate endothelial barrier function by controlling pericellular permeability of vasculature. Here, we describe methods for both visualizing and quantifying junctional permeability and barrier changes in endothelial monolayers in vitro. PMID:21874457

  3. Evolving functions of endothelial cells in inflammation.

    PubMed

    Pober, Jordan S; Sessa, William C

    2007-10-01

    Inflammation is usually analysed from the perspective of tissue-infiltrating leukocytes. Microvascular endothelial cells at a site of inflammation are both active participants in and regulators of inflammatory processes. The properties of endothelial cells change during the transition from acute to chronic inflammation and during the transition from innate to adaptive immunity. Mediators that act on endothelial cells also act on leukocytes and vice versa. Consequently, many anti-inflammatory therapies influence the behaviour of endothelial cells and vascular therapeutics influence inflammation. This Review describes the functions performed by endothelial cells at each stage of the inflammatory process, emphasizing the principal mediators and signalling pathways involved and the therapeutic implications. PMID:17893694

  4. Analysis of endothelial barrier function in vitro.

    PubMed

    Wang, Yuping; Alexander, J Steven

    2011-01-01

    Increased microvascular solute permeability underlies many forms of pathophysiological conditions, including inflammation. Endothelial monolayer cultures provide an excellent model system which allows systemic and mechanistic study of endothelial barrier function and paracellular permeability in vitro. The endothelial-specific complexus adherens junction protein VE-cadherin and their intracellular complex form pericellular structures along the cell borders which are critical to regulate endothelial barrier function by controlling pericellular permeability of vasculature. Here, we describe methods for both visualizing and quantifying junctional permeability and barrier changes in endothelial monolayers in vitro. PMID:21874457

  5. Adaptive response of vascular endothelial cells to an acute increase in shear stress frequency

    PubMed Central

    Zhang, Ji

    2013-01-01

    Local shear stress sensed by arterial endothelial cells is occasionally altered by changes in global hemodynamic parameters, e.g., heart rate and blood flow rate, as a result of normal physiological events, such as exercise. In a recently study (41), we demonstrated that during the adaptive response to increased shear magnitude, porcine endothelial cells exhibited an unique phenotype featuring a transient increase in permeability and the upregulation of a set of anti-inflammatory and antioxidative genes. In the present study, we characterize the adaptive response of these cells to an increase in shear frequency, another important hemodynamic parameter with implications in atherogenesis. Endothelial cells were preconditioned by a basal-level sinusoidal shear stress of 15 ± 15 dyn/cm2 at 1 Hz, and the frequency was then elevated to 2 Hz. Endothelial permeability increased slowly after the frequency step-up, but the increase was relatively small. Using microarrays, we identified 37 genes that are sensitive to the frequency step-up. The acute increase in shear frequency upregulates a set of cell-cycle regulation and angiogenesis-related genes. The overall adaptive response to the increased frequency is distinctly different from that to a magnitude step-up. However, consistent with the previous study, our data support the notion that endothelial function during an adaptive response is different than that of fully adapted endothelial cells. Our studies may also provide insights into the beneficial effects of exercise on vascular health: transient increases in frequency may facilitate endothelial repair, whereas similar increases in shear magnitude may keep excessive inflammation and oxidative stress at bay. PMID:23851277

  6. Endothelial Plasticity: Shifting Phenotypes through Force Feedback

    PubMed Central

    Krenning, Guido; Barauna, Valerio G.; Krieger, José E.; Harmsen, Martin C.; Moonen, Jan-Renier A. J.

    2016-01-01

    The endothelial lining of the vasculature is exposed to a large variety of biochemical and hemodynamic stimuli with different gradients throughout the vascular network. Adequate adaptation requires endothelial cells to be highly plastic, which is reflected by the remarkable heterogeneity of endothelial cells in tissues and organs. Hemodynamic forces such as fluid shear stress and cyclic strain are strong modulators of the endothelial phenotype and function. Although endothelial plasticity is essential during development and adult physiology, proatherogenic stimuli can induce adverse plasticity which contributes to disease. Endothelial-to-mesenchymal transition (EndMT), the hallmark of endothelial plasticity, was long thought to be restricted to embryonic development but has emerged as a pathologic process in a plethora of diseases. In this perspective we argue how shear stress and cyclic strain can modulate EndMT and discuss how this is reflected in atherosclerosis and pulmonary arterial hypertension. PMID:26904133

  7. Base Excision Repair and Cancer

    PubMed Central

    Wallace, Susan S.; Murphy, Drew L.; Sweasy, Joann B.

    2012-01-01

    Base excision repair is the system used from bacteria to man to remove the tens of thousands of endogenous DNA damages produced daily in each human cell. Base excision repair is required for normal mammalian development and defects have been associated with neurological disorders and cancer. In this paper we provide an overview of short patch base excision repair in humans and summarize current knowledge of defects in base excision repair in mouse models and functional studies on short patch base excision repair germ line polymorphisms and their relationship to cancer. The biallelic germ line mutations that result in MUTYH-associated colon cancer are also discussed. PMID:22252118

  8. Small molecules that promote regenerative repair for pancreatic and cardiovascular health.

    PubMed

    Menhaji-Klotz, Elnaz; Price, David A

    2015-12-01

    Regenerative medicine for repair of organ injury is an emerging area of research. The use of embryonic stem cells and induced pluripotent cells in combination with endogenously expressed growth factors has provided methods to generate differentiated cells for cell-based therapy and for screening purposes. As cell-based therapies continue to be investigated in the clinical setting, small molecules for in situ tissue repair are being reported. In this review, we focus on the reports applicable to the field of cardiovascular and metabolic disease by discussing small molecules that target β-cells, cardiomyocytes and endothelial cells.

  9. Nuclear p120 catenin unlocks mitotic block of contact-inhibited human corneal endothelial monolayers without disrupting adherent junctions.

    PubMed

    Zhu, Ying-Ting; Chen, Hung-Chi; Chen, Szu-Yu; Tseng, Scheffer C G

    2012-08-01

    Contact inhibition ubiquitously exists in non-transformed cells that are in contact with neighboring cells. This phenomenon explains the poor regenerative capacity of in vivo human corneal endothelial cells during aging, injury and surgery. This study demonstrated that the conventional approach of expanding human corneal endothelial cells by disrupting contact inhibition with EDTA followed by bFGF activated canonical Wnt signaling and lost the normal phenotype to endothelial-mesenchymal transition, especially if TGFβ1 was added. By contrast, siRNA against p120 catenin (CTNND1) also uniquely promoted proliferation of the endothelial cells by activating trafficking of p120 catenin to the nucleus, thus relieving repression by nuclear Kaiso. This nuclear p120-catenin-Kaiso signaling is associated with activation of RhoA-ROCK signaling, destabilization of microtubules and inhibition of Hippo signaling, but not with activation of Wnt-β-catenin signaling. Consequently, proliferating human corneal endothelial cells maintained a hexagonal shape, with junctional expression of N-cadherin, ZO-1 and Na(+)/K(+)-ATPase. Further expansion of human corneal endothelial monolayers with a normal phenotype and a higher density was possible by prolonging treatment with p120 catenin siRNA followed by its withdrawal. This new strategy of perturbing contact inhibition by selective activation of p120-catenin-Kaiso signaling without disrupting adherent junction could be used to engineer surgical grafts containing normal human corneal endothelial cells to meet a global corneal shortage and for endothelial keratoplasties. PMID:22505615

  10. Semi-Automated Diagnosis, Repair, and Rework of Spacecraft Electronics

    NASA Technical Reports Server (NTRS)

    Struk, Peter M.; Oeftering, Richard C.; Easton, John W.; Anderson, Eric E.

    2008-01-01

    NASA's Constellation Program for Exploration of the Moon and Mars places human crews in extreme isolation in resource scarce environments. Near Earth, the discontinuation of Space Shuttle flights after 2010 will alter the up- and down-mass capacity for the International Space Station (ISS). NASA is considering new options for logistics support strategies for future missions. Aerospace systems are often composed of replaceable modular blocks that minimize the need for complex service operations in the field. Such a strategy however, implies a robust and responsive logistics infrastructure with relatively low transportation costs. The modular Orbital Replacement Units (ORU) used for ISS requires relatively large blocks of replacement hardware even though the actual failed component may really be three orders of magnitude smaller. The ability to perform in-situ repair of electronics circuits at the component level can dramatically reduce the scale of spares and related logistics cost. This ability also reduces mission risk, increases crew independence and improves the overall supportability of the program. The Component-Level Electronics Assembly Repair (CLEAR) task under the NASA Supportability program was established to demonstrate the practicality of repair by first investigating widely used soldering materials and processes (M&P) performed by modest manual means. The work will result in program guidelines for performing manual repairs along with design guidance for circuit reparability. The next phase of CLEAR recognizes that manual repair has its limitations and some highly integrated devices are extremely difficult to handle and demand semi-automated equipment. Further, electronics repairs require a broad range of diagnostic capability to isolate the faulty components. Finally repairs must pass functional tests to determine that the repairs are successful and the circuit can be returned to service. To prevent equipment demands from exceeding spacecraft volume

  11. Gene Therapy for Cartilage Repair

    PubMed Central

    Madry, Henning; Orth, Patrick; Cucchiarini, Magali

    2011-01-01

    The concept of using gene transfer strategies for cartilage repair originates from the idea of transferring genes encoding therapeutic factors into the repair tissue, resulting in a temporarily and spatially defined delivery of therapeutic molecules to sites of cartilage damage. This review focuses on the potential benefits of using gene therapy approaches for the repair of articular cartilage and meniscal fibrocartilage, including articular cartilage defects resulting from acute trauma, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Possible applications for meniscal repair comprise meniscal lesions, meniscal sutures, and meniscal transplantation. Recent studies in both small and large animal models have demonstrated the applicability of gene-based approaches for cartilage repair. Chondrogenic pathways were stimulated in the repair tissue and in osteoarthritic cartilage using genes for polypeptide growth factors and transcription factors. Although encouraging data have been generated, a successful translation of gene therapy for cartilage repair will require an ongoing combined effort of orthopedic surgeons and of basic scientists. PMID:26069580

  12. Substrates for Expansion of Corneal Endothelial Cells towards Bioengineering of Human Corneal Endothelium

    PubMed Central

    Navaratnam, Jesintha; Utheim, Tor P.; Rajasekhar, Vinagolu K.; Shahdadfar, Aboulghassem

    2015-01-01

    Corneal endothelium is a single layer of specialized cells that lines the posterior surface of cornea and maintains corneal hydration and corneal transparency essential for vision. Currently, transplantation is the only therapeutic option for diseases affecting the corneal endothelium. Transplantation of corneal endothelium, called endothelial keratoplasty, is widely used for corneal endothelial diseases. However, corneal transplantation is limited by global donor shortage. Therefore, there is a need to overcome the deficiency of sufficient donor corneal tissue. New approaches are being explored to engineer corneal tissues such that sufficient amount of corneal endothelium becomes available to offset the present shortage of functional cornea. Although human corneal endothelial cells have limited proliferative capacity in vivo, several laboratories have been successful in in vitro expansion of human corneal endothelial cells. Here we provide a comprehensive analysis of different substrates employed for in vitro cultivation of human corneal endothelial cells. Advances and emerging challenges with ex vivo cultured corneal endothelial layer for the ultimate goal of therapeutic replacement of dysfunctional corneal endothelium in humans with functional corneal endothelium are also presented. PMID:26378588

  13. Polymeric stent materials dysregulate macrophage and endothelial cell functions: implications for coronary artery stent

    PubMed Central

    Wang, Xintong; Zachman, Angela L.; Chun, Young Wook; Shen, Fang-Wen; Hwang, Yu-Shik; Sung, Hak-Joon

    2014-01-01

    Background Biodegradable polymers have been applied as bulk or coating materials for coronary artery stents. The degradation of polymers, however, could induce endothelial dysfunction and aggravate neointimal formation. Here we use polymeric microparticles to simulate and demonstrate the effects of degraded stent materials on phagocytic activity, cell death and dysfunction of macrophages and endothelial cells. Methods Microparticles made of low molecular weight polyesters were incubated with human macrophages and coronary artery endothelial cells (ECs). Microparticle-induced phagocytosis, cytotoxicity, apoptosis, cytokine release and surface marker expression were determined by immunostaining or ELISA. Elastase expression was analyzed by ELISA and the elastase-mediated polymer degradation was assessed by mass spectrometry. Results We demonstrated poly(D,L-lactic acid) (PLLA) and polycaprolactone (PCL) microparticles induced cytotoxicity in macrophages and ECs, partially through cell apoptosis. The particle treatment alleviated EC phagocytosis, as opposed to macrophages, but enhanced the expression of vascular cell adhesion molecule-1 (VCAM) along with decreased nitric oxide production, indicating ECs were activated and lost their capacity to maintain homeostasis. The activation of both cell types induced release of elastase or elastase-like protease, which further accelerated polymer degradation. Conclusions This study revealed that low molecule weight PLLA and PCL microparticles increased cytotoxicity and dysregulated endothelial cell function, which in turn enhanced elastase release and polymer degradation. These indicate polymer or polymer-coated stents impose a risk of endothelial dysfunction after deployment which can potentially lead to delayed endothelialization, neointimal hyperplasia and late thrombosis. PMID:24820736

  14. The effect of donor variation and senescence on endothelial differentiation of human mesenchymal stromal cells.

    PubMed

    Portalska, Karolina Janeczek; Groen, Nathalie; Krenning, Guido; Georgi, Nicole; Mentink, Anouk; Harmsen, Martin C; van Blitterswijk, Clemens; de Boer, Jan

    2013-11-01

    Application of autologous cells is considered for a broad range of regenerative therapies because it is not surrounded by the immunological and ethical issues of allo- or xenogenic cells. However, isolation, expansion, and application of autologous cells do suffer from variability in therapeutic efficacy due to donor to donor differences and due to prolonged culture. One important source of autologous cells is mesenchymal stromal cells (MSCs), which can differentiate toward endothelial-like cells, thus making them an ideal candidate as cell source for tissue vascularization. Here we screened MSCs from 20 donors for their endothelial differentiation capacity and correlated it with the gene expression profile of the whole genome in the undifferentiated state. Cells of all donors were able to form tubes on Matrigel and induced the expression of endothelial genes, although with quantitative differences. In addition, we analyzed the effect of prolonged in vitro expansion on the multipotency of human MSCs and found that endothelial differentiation is only mildly sensitive to expansion-induced loss of differentiation as compared to osteogenic and adipogenic differentiation. Our results show the robustness of the endothelial differentiation protocol and the gene expression data give insight in the differences in endothelial differentiation between donors.

  15. The natural antioxidants, pomegranate extract and soy isoflavones, favourably modulate canine endothelial cell function.

    PubMed

    Baumgartner-Parzer, Sabina M; Waldenberger, Ferdinand Rudolf; Freudenthaler, Angelika; Ginouvès-Guerdoux, Amandine; McGahie, David; Gatto, Hugues

    2012-01-01

    Cardiovascular disease, preceded by vascular endothelial dysfunction, is a prominent cause of death in dogs. L-carnitine and taurine, well known for their antioxidative capacity, beneficially affect cardiovascular disease as well as certain dog cardiomyopathies. It is well established that vascular endothelial dysfunction precedes cardiovascular disease and that "vasoprotective factors" (NO and antioxidants) prevent apoptosis, whereas "risk factors" such as oxidized LDL, hyperglycemia, and free fatty acids trigger it in cultured human vascular endothelial cells. Whereas human vascular cell in vitro models are widely established and used for the characterisation of potential vasoprotective substances, such models are not available for canine endothelial cells. In the present study we therefore developed an in vitro model, which allows the testing of the effects of different substances on proliferation and apoptosis in canine aortic endothelial cells. This model was used to test L-carnitine, taurine, pomegranate extract, and Soy Isoflavones in comparison to reference substances (glutathione and pioglitazone) previously shown to modulate human endothelial cell function. L-carnitine and taurine neither exhibited antiproliferative nor antiapoptotic activities in the context of this study. However extracts from pomegranate and soy isoflavones dramatically reduced proliferation and apoptosis in a dose dependent fashion, being in line with a vasoprotective activity in dogs.

  16. Loss of Siah2 does not impact angiogenic potential of murine endothelial cells.

    PubMed

    Wong, Christina S F; Chen, Anna; Liu, Mira C P; Parker, Belinda S; Möller, Andreas

    2015-11-01

    Angiogenesis is triggered in response to hypoxia under many circumstances, from healthy cells and tissues during embryogenesis to pathological conditions like the formation of new blood vessels to supply tumours and promote invasive cancer. Siah2 has been shown to regulate the hypoxia pathway upstream of hypoxia-induced transcription factor subunit Hif-1alpha, and therefore may play an important role in angiogenesis in response to hypoxic stress in endothelial cells. This study aims to investigate the basic function of Siah2 in endothelial cells under hypoxia and to test the ability of Siah2 deficient cells to mount an angiogenic response when deprived of oxygen. We and others have previously shown that Siah2 is crucial for mediating the hypoxic response in many different cell types studied. In this study however, we describe that Siah2(-/-) endothelial cells have an intact hypoxic signalling pathway, including Hif-1alpha stabilisation and gene expression, the first report of a tissue or cell lineage in which the loss of Siah2 does not seem to impact hypoxic response signalling. In mice, the infiltration of Siah2(-/-) endothelial cells into a Matrigel plug containing a VEGF-A attractant was similar compared with wildtype endothelial cells. Ex vivo however, there was a reduced capacity of Siah2(-/-) aorta to form tubes or new vessels. Thus, we conclude that Siah2 is not essential for the hypoxic response of endothelial cells.

  17. CD44-related chondroitin sulfate proteoglycan, a cell surface receptor implicated with tumor cell invasion, mediates endothelial cell migration on fibrinogen and invasion into a fibrin matrix.

    PubMed Central

    Henke, C A; Roongta, U; Mickelson, D J; Knutson, J R; McCarthy, J B

    1996-01-01

    Microvascular endothelial cell invasion into the fibrin provisional matrix is an integral component of angiogenesis during wound repair. Cell surface receptors which interact with extracellular matrix proteins participate in cell migration and invasion. Malignant cells use CD44-related chondroitin sulfate proteoglycan (CSPG) as a matrix receptor to mediate migration and invasion. In this study, we examine whether cell surface CSPG can mediate similar events in nonmalignant wound microvascular endothelial cells or whether use of CSPG for migration and invasion is a property largely restricted to malignant cells. After inhibiting CSPG synthesis with p-nitrophenyl beta-d xylopyranoside (beta-d xyloside), wound microvascular endothelial cells were capable of attaching and spreading on the surface of a fibrin gel; however, their ability to invade the fibrin matrix was virtually eliminated. To begin to examine the mechanism by which endothelial cells use CSPG to invade fibrin matrices, cell adhesion and migration on fibrinogen was examined. Endothelial cell adhesion and migration on fibrinogen were inhibited by both beta-d xyloside and after cleavage of chondroitin sulfate from the core protein by chondroitinase ABC. We have determined that wound microvascular endothelial cells express the majority of their proteoglycan as CSPG and that the CSPG core protein is immunologically related to CD44. PCR studies show that these cells express both the "standard" (CD44H) isoform and an isoform containing the variably spliced exon V3. In addition, anti-CD44 antibody blocks endothelial cell migration on fibrinogen. Affinity chromatography studies reveal that partially purified microvascular endothelial cell CSPG binds fibrinogen. These findings suggest that CD44-related CSPG, a molecule implicated in the invasive behavior of tumor cells, is capable of binding fibrinogen/fibrin, thereby mediating endothelial cell migration and invasion into the fibrin provisional matrix during wound

  18. Salt controls endothelial and vascular phenotype.

    PubMed

    Kusche-Vihrog, Kristina; Schmitz, Boris; Brand, Eva

    2015-03-01

    High salt (NaCl) intake promotes the development of vascular diseases independent of a rise in blood pressure, whereas reduction of salt consumption has beneficial effects for the arterial system. This article summarizes our current understanding of the molecular mechanisms of high salt-induced alterations of the endothelial phenotype, the impact of the individual endothelial genotype, and the overall vascular phenotype. We focus on the endothelial Na(+) channel (EnNaC)-controlled nanomechanical properties of the endothelium, since high Na(+) leads to an EnNaC-induced Na(+)-influx and subsequent stiffening of endothelial cells. The mechanical stiffness of the endothelial cell (i.e., the endothelial phenotype) plays a crucial role as it controls the production of the endothelium-derived vasodilator nitric oxide (NO) which directly affects the tone of the vascular smooth muscle cells. In contrast to soft endothelial cells, stiff endothelial cells release reduced amounts of NO, the hallmark of endothelial dysfunction. This endothelium-born process is followed by the development of arterial stiffness (i.e., the vascular phenotype), predicting the development of vascular end-organ damage such as myocardial infarction, stroke, and renal impairment. In this context, we outline the potential clinical implication of direct (amiloride) and indirect (spironolactone) EnNaC inhibition on vascular function. However, interindividual differences exist in the response to high salt intake which involves different endothelial genotypes. Thus, selected genes and genetic variants contributing to the development of salt-induced endothelial dysfunction and hypertension are discussed. In this review, we focus on the role of salt in endothelial and vascular (dys)function and the link between salt-induced changes of the endothelial and vascular phenotype and its clinical implications.

  19. Culture of human endothelial cells.

    PubMed

    Gallicchio, M A

    2001-01-01

    Endothelial cells line the luminal surface of all blood vessels in the body. The endothelial surface in adult humans is composed of approximately l-6×l0(13) cells and covers an area of 1-7 m(2). Endothelium serves many functions, including fluid and solute exchange through cell contraction, provision of an antithrombogenic surface through tissue plasminogen activator (tPA) and prostacyclin release, synthesis of angiogenic factors such as adenosine, allowance of leukocyte trafficking through adhesion molecule synthesis, presentation of antigens to the immune system, maintenance of vascular tone through nitric oxide and endothelin synthesis, and metabolism of circulating molecules through the release of enzymes such as lipoprotein lipase. PMID:21340938

  20. Do incretins improve endothelial function?

    PubMed Central

    2014-01-01

    An impaired endothelial function has been recognized in the early stage of atherosclerosis, and is a major factor affecting the future development of cardiovascular events. Type 2 diabetes mellitus (T2DM) is widely prevalent, and is one of the most important risk factors for cardiovascular disease. T2DM is associated with increases in both morbidity and mortality, particularly from cardiovascular disease. New therapies based on the incretin hormone and its actions are now becoming widely used, and appear to offer advantages over conventional therapies by keeping the body weight steady and limiting hypoglycemia, while also achieving attractive glycemic control. However, there is little data available about the effects of incretins on the cardiovascular system. This review will focus on the effects of incretin therapies, including glucagon-like peptide-1 (GLP-1) analogs and dipeptidyl peptidase (DPP)-4 inhibitors, on the endothelial function, and will discuss the potential mechanisms underlying these effects. PMID:24428883

  1. Flow-Mediated Endothelial Mechanotransduction

    PubMed Central

    Davies, Peter F.

    2011-01-01

    Mechanical forces associated with blood flow play important roles in the acute control of vascular tone, the regulation of arterial structure and remodeling, and the localization of atherosclerotic lesions. Major regulation of the blood vessel responses occurs by the action of hemodynamic shear stresses on the endothelium. The transmission of hemodynamic forces throughout the endothelium and the mechanotransduction mechanisms that lead to biophysical, biochemical, and gene regulatory responses of endothelial cells to hemodynamic shear stresses are reviewed. PMID:7624393

  2. Decrease of fibrinolytic activity in human endothelial cells by arsenite.

    PubMed

    Jiang, Shinn-Jong; Lin, Tsun-Mei; Wu, Hua-Lin; Han, Huai-Song; Shi, Guey-Yueh

    2002-01-01

    Blackfoot disease (BFD) is an endemic peripheral vascular occlusive disease that occurred in the southwest coast of Taiwan. It is believed that arsenic in the drinking water from artesian wells plays an important role in the development of the disease. We have previously shown that BFD patients had significant lower tissue-type plasminogen activator (t-PA) antigen level and higher plasminogen activator inhibitor, Type 1 (PAI-1) antigen level than normal controls. The purpose of this study was to investigate the effects of arsenite on the fibrinolytic and anticoagulant activities of cultured macrovascular and microvascular endothelial cells. Incubation of human microvascular endothelial cells (HMEC-1), but not human umbilical vein endothelial cells (HUVECs), with arsenite caused a decrease of t-PA mRNA level, a rise of both PAI-1 mRNA level and PAI activity. Arsenite could also inhibit the thrombomodulin (TM) mRNA expression and reduce the TM antigen level in HMEC-1. In conclusion, arsenite had a greater effect on HMEC-1 as compared to HUVECs in lowering the fibrinolytic activity and may be responsible for the reduced capacity of fibrinolysis associated with BFD.

  3. Endothelial Targeting of Cowpea Mosaic Virus (CPMV) via Surface Vimentin

    PubMed Central

    Koudelka, Kristopher J.; Destito, Giuseppe; Plummer, Emily M.; Trauger, Sunia A.; Siuzdak, Gary; Manchester, Marianne

    2009-01-01

    Cowpea mosaic virus (CPMV) is a plant comovirus in the picornavirus superfamily, and is used for a wide variety of biomedical and material science applications. Although its replication is restricted to plants, CPMV binds to and enters mammalian cells, including endothelial cells and particularly tumor neovascular endothelium in vivo. This natural capacity has lead to the use of CPMV as a sensor for intravital imaging of vascular development. Binding of CPMV to endothelial cells occurs via interaction with a 54 kD cell-surface protein, but this protein has not previously been identified. Here we identify the CPMV binding protein as a cell-surface form of the intermediate filament vimentin. The CPMV-vimentin interaction was established using proteomic screens and confirmed by direct interaction of CPMV with purified vimentin, as well as inhibition in a vimentin-knockout cell line. Vimentin and CPMV were also co-localized in vascular endothelium of mouse and rat in vivo. Together these studies indicate that surface vimentin mediates binding and may lead to internalization of CPMV in vivo, establishing surface vimentin as an important vascular endothelial ligand for nanoparticle targeting to tumors. These results also establish vimentin as a ligand for picornaviruses in both the plant and animal kingdoms of life. Since bacterial pathogens and several other classes of viruses also bind to surface vimentin, these studies suggest a common role for surface vimentin in pathogen transmission. PMID:19412526

  4. Endothelial microparticles as conveyors of information in atherosclerotic disease.

    PubMed

    Schiro, A; Wilkinson, F L; Weston, R; Smyth, J V; Serracino-Inglott, F; Alexander, M Y

    2014-06-01

    Endothelial microparticles (EMPs) are complex submicron membrane-shed vesicles released into the circulation following endothelium cell activation or apoptosis. They are classified as either physiological or pathological, with anticoagulant or pro-inflammatory effects respectively. Endothelial dysfunction caused by inflammation is a key initiating event in atherosclerotic plaque formation. Athero-emboli, resulting from ruptured carotid plaques are a major cause of stroke. Current clinical techniques for arterial assessment, angiography and carotid ultrasound, give accurate information about stenosis but limited evidence on plaque composition, inflammation or vulnerability; as a result, patients with asymptomatic, or fragile carotid lesions, may not be identified and treated effectively. There is a need to discover novel biomarkers and develop more efficient diagnostic approaches in order to stratify patients at most risk of stroke, who would benefit from interventional surgery. Increasing evidence suggests that EMPs play an important role in the pathogenesis of cardiovascular disease, acting as a marker of damage, either exacerbating disease progression or triggering a repair response. In this regard, it has been suggested that EMPs have the potential to act as biomarkers of disease status. In this review, we will present the evidence to support this hypothesis and propose a novel concept for the development of a diagnostic device that could be implemented in the clinic. PMID:24721189

  5. Fullerene derivatives protect endothelial cells against NO-induced damage

    NASA Astrophysics Data System (ADS)

    Lao, Fang; Li, Wei; Han, Dong; Qu, Ying; Liu, Ying; Zhao, Yuliang; Chen, Chunying

    2009-06-01

    Functional fullerene derivatives have been demonstrated with potent antioxidation properties. Nitric oxide (NO) is a free radical that plays a part in leading to brain damage when it is accumulated to a high concentration. The possible scavenging activity of NO by the hydroxylated fullerene derivative C60(OH)22 and malonic acid derivative C60(C(COOH)2)2 was investigated using primary rat brain cerebral microvessel endothelial cells (CMECs). Results demonstrate that sodium nitroprusside (SNP), used as an NO donor, caused a marked decrease in cell viability and an increase in apoptosis. However, fullerene derivatives can remarkably protect against the apoptosis induced by NO assault. In addition, fullerene derivatives can also prevent NO-induced depolymerization of cytoskeleton and damage of the nucleus and accelerate endothelial cell repair. Further investigation shows that the sudden increase of the intercellular reactive oxygen species (ROS) induced by NO was significantly attenuated by post-treatment with fullerene derivatives. Our results suggest that functional fullerene derivatives are potential applications for NO-related disorders.

  6. Production, Purification, and Characterization of 15N-Labeled DNA Repair Proteins as Internal Standards for Mass Spectrometric Measurements

    PubMed Central

    Jaruga, Pawel; Nelson, Bryant C.; Lowenthal, Mark S.; Jemth, Ann-Sofie; Loseva, Olga; Coskun, Erdem; Helleday, Thomas

    2016-01-01

    Oxidatively induced DNA damage is caused in living organisms by a variety of damaging agents, resulting in the formation of a multiplicity of lesions, which are mutagenic and cytotoxic. Unless repaired by DNA repair mechanisms before DNA replication, DNA lesions can lead to genomic instability, which is one of the hallmarks of cancer. Oxidatively induced DNA damage is mainly repaired by base excision repair pathway with the involvement of a plethora of proteins. Cancer tissues develop greater DNA repair capacity than normal tissues by overexpressing DNA repair proteins. Increased DNA repair in tumors that removes DNA lesions generated by therapeutic agents before they became toxic is a major mechanism in the development of therapy resistance. Evidence suggests that DNA repair capacity may be a predictive biomarker of patient response. Thus, knowledge of DNA–protein expressions in disease-free and cancerous tissues may help predict and guide development of treatments and yield the best therapeutic response. Our laboratory has developed methodologies that use mass spectrometry with isotope dilution for the measurement of expression of DNA repair proteins in human tissues and cultured cells. For this purpose, full-length 15N-labeled analogs of a number of human DNA repair proteins have been produced and purified to be used as internal standards for positive identification and accurate quantification. This chapter describes in detail the protocols of this work. The use of 15N-labeled proteins as internal standards for the measurement of several DNA repair proteins in vivo is also presented. PMID:26791985

  7. A Novel Molecular and Functional Stemness Signature Assessing Human Cord Blood-Derived Endothelial Progenitor Cell Immaturity

    PubMed Central

    Pascaud, Juliette; Driancourt, Catherine; Boyer-Di-Ponio, Julie; Uzan, Georges

    2016-01-01

    Endothelial Colony Forming Cells (ECFCs), a distinct population of Endothelial Progenitor Cells (EPCs) progeny, display phenotypic and functional characteristics of endothelial cells while retaining features of stem/progenitor cells. Cord blood-derived ECFCs (CB-ECFCs) have a high clonogenic and proliferative potentials and they can acquire different endothelial phenotypes, this requiring some plasticity. These properties provide angiogenic and vascular repair capabilities to CB-ECFCs for ischemic cell therapies. However, the degree of immaturity retained by EPCs is still confused and poorly defined. Consequently, to better characterize CB-ECFC stemness, we quantified their clonogenic potential and demonstrated that they were reprogrammed into induced pluripotent stem cells (iPSCs) more efficiently and rapidly than adult endothelial cells. Moreover, we analyzed the transcriptional profile of a broad gene panel known to be related to stem cells. We showed that, unlike mature endothelial cells, CB-ECFCs expressed genes involved in the maintenance of embryonic stem cell properties such as DNMT3B, GDF3 or SOX2. Thus, these results provide further evidence and tools to appreciate EPC-derived cell stemness. Moreover this novel stem cell transcriptional signature of ECFCs could help better characterizing and ranging EPCs according to their immaturity profile. PMID:27043207

  8. Lin28 enhances tissue repair by reprogramming cellular metabolism

    PubMed Central

    Shyh-Chang, Ng; Zhu, Hao; de Soysa, T. Yvanka; Shinoda, Gen; Seligson, Marc T.; Tsanov, Kaloyan M.; Nguyen, Liem; Asara, John M.; Cantley, Lewis C.; Daley, George Q.

    2014-01-01

    SUMMARY Regeneration capacity declines with age, but why juvenile organisms show enhanced tissue repair remains unexplained. Lin28a, a highly-conserved RNA binding protein expressed during embryogenesis, plays roles in development, pluripotency and metabolism. To determine if Lin28a might influence tissue repair in adults, we engineered the reactivation of Lin28a expression in several models of tissue injury. Lin28a reactivation improved hair regrowth by promoting anagen in hair follicles, and accelerated regrowth of cartilage, bone and mesenchyme after ear and digit injuries. Lin28a inhibits let-7 microRNA biogenesis; however let-7 repression was necessary but insufficient to enhance repair. Lin28a bound to and enhanced the translation of mRNAs for several metabolic enzymes, thereby increasing glycolysis and oxidative phosphorylation (OxPhos). Lin28a-mediated enhancement of tissue repair was negated by OxPhos inhibition, whereas a pharmacologically-induced increase in OxPhos enhanced repair. Thus, Lin28a enhances tissue repair in some adult tissues by reprogramming cellular bioenergetics. PMID:24209617

  9. Endothelial heterogeneity in the umbilico-placental unit: DNA methylation as an innuendo of epigenetic diversity

    PubMed Central

    Casanello, Paola; Schneider, Daniela; Herrera, Emilio A.; Uauy, Ricardo; Krause, Bernardo J.

    2014-01-01

    The endothelium is a multifunctional heterogeneous tissue playing a key role in the physiology of every organ. To accomplish this role the endothelium presents a phenotypic diversity that is early prompted during vascular development, allowing it to cope with specific requirements in a time- and site-specific manner. During the last decade several reports show that endothelial diversity is also present in the umbilico-placental vasculature, with differences between macro- and microvascular vessels as well as arterial and venous endothelium. This diversity is evidenced in vitro as a higher angiogenic capacity in the microcirculation; or disparity in the levels of several molecules that control endothelial function (i.e., receptor for growth factors, vasoactive mediators, and adhesion molecules) which frequently are differentially expressed between arterial and venous endothelium. Emerging evidence suggests that endothelial diversity would be prominently driven by epigenetic mechanisms which also control the basal expression of endothelial-specific genes. This review outlines evidence for endothelial diversity since early stages of vascular development and how this heterogeneity is expressed in the umbilico-placental vasculature. Furthermore a brief picture of epigenetic mechanisms and their role on endothelial physiology emphasizing new data on umbilical and placental endothelial cells is presented. Unraveling the role of epigenetic mechanisms on long term endothelial physiology and its functional diversity would contribute to develop more accurate therapeutic interventions. Altogether these data show that micro- versus macro-vascular, or artery versus vein comparisons are an oversimplification of the complexity occurring in the endothelium at different levels, and the necessity for the future research to establish the precise source of cells which are under study. PMID:24723887

  10. Vascular smooth muscle progenitor cells: building and repairing blood vessels.

    PubMed

    Majesky, Mark W; Dong, Xiu Rong; Regan, Jenna N; Hoglund, Virginia J

    2011-02-01

    Molecular pathways that control the specification, migration, and number of available smooth muscle progenitor cells play key roles in determining blood vessel size and structure, capacity for tissue repair, and progression of age-related disorders. Defects in these pathways produce malformations of developing blood vessels, depletion of smooth muscle progenitor cell pools for vessel wall maintenance and repair, and aberrant activation of alternative differentiation pathways in vascular disease. A better understanding of the molecular mechanisms that uniquely specify and maintain vascular smooth muscle cell precursors is essential if we are to use advances in stem and progenitor cell biology and somatic cell reprogramming for applications directed to the vessel wall.

  11. Mobilization of Circulating Endothelial Progenitor Cells Correlates with the Clinical Course of Hantavirus Disease

    PubMed Central

    Grouls, Stephan; Hettwer, David; Rafat, Neysan; Tönshoff, Burkhard; Zeier, Martin

    2014-01-01

    Infections with hemorrhagic fever viruses are characterized by increased permeability leading to capillary leakage. Hantavirus infection is associated with endothelial dysfunction, and the clinical course is related to the degree of vascular injury. Circulating endothelial progenitor cells (cEPCs) play a pivotal role in the repair of the damaged endothelium. Therefore, we analyzed the number of cEPCs and their mobilizing growth factors in patients suffering from hantavirus disease induced by infection with Puumala virus. The numbers of EPCs of 36 hantavirus-infected patients and age- and gender-matched healthy controls were analyzed by flow cytometry. Concentrations of cEPC-mobilizing growth factors in plasma were determined by enzyme-linked immunosorbent assay. Laboratory parameters were correlated with the number of cEPCs. In patients infected with hantavirus, the number of cEPCs was significantly higher than that in healthy controls. Levels of mobilizing cytokines were upregulated in patients, and the mobilization of cEPCs is paralleled with the normalization of clinical parameters. Moreover, higher levels of cEPCs correlated with higher serum albumin levels and platelet concentrations. Our data indicate that cEPCs may play a role in the repair of hantavirus-induced endothelial damage, thereby influencing the clinical course and the severity of symptoms. PMID:24155401

  12. Novel regulators of endothelial barrier function

    PubMed Central

    Ravindran, Krishnan; Kuebler, Wolfgang M.

    2014-01-01

    Endothelial barrier function is an essential and tightly regulated process that ensures proper compartmentalization of the vascular and interstitial space, while allowing for the diffusive exchange of small molecules and the controlled trafficking of macromolecules and immune cells. Failure to control endothelial barrier integrity results in excessive leakage of fluid and proteins from the vasculature that can rapidly become fatal in scenarios such as sepsis or the acute respiratory distress syndrome. Here, we highlight recent advances in our understanding on the regulation of endothelial permeability, with a specific focus on the endothelial glycocalyx and endothelial scaffolds, regulatory intracellular signaling cascades, as well as triggers and mediators that either disrupt or enhance endothelial barrier integrity, and provide our perspective as to areas of seeming controversy and knowledge gaps, respectively. PMID:25381026

  13. Replication of human endothelial cells in culture.

    PubMed

    Lewis, L J; Hoak, J C; Maca, R D; Fry, G L

    1973-08-01

    Investigative studies dealing with the properties and functions of endothelial cells have been hampered because there has been little or no success in the isolation, growth, and passage of individual cells in large numbers. We have developed a system whereby pure cultures of endothelial cells derived from umbilical veins can be subcultured for at least five serial passages. Many facets of endothelial function and interaction can be evaluated with the use of this new adaptive system of isolation and culture. PMID:4718112

  14. Defective DSB repair correlates with abnormal nuclear morphology and is improved with FTI treatment in Hutchinson-Gilford progeria syndrome fibroblasts

    SciTech Connect

    Constantinescu, Dan; Csoka, Antonei B.; Navara, Christopher S.; Schatten, Gerald P.

    2010-10-15

    Impaired DSB repair has been implicated as a molecular mechanism contributing to the accelerating aging phenotype in Hutchinson-Gilford progeria syndrome (HGPS), but neither the extent nor the cause of the repair deficiency has been fully elucidated. Here we perform a quantitative analysis of the steady-state number of DSBs and the repair kinetics of ionizing radiation (IR)-induced DSBs in HGPS cells. We report an elevated steady-state number of DSBs and impaired repair of IR-induced DSBs, both of which correlated strongly with abnormal nuclear morphology. We recreated the HGPS cellular phenotype in human coronary artery endothelial cells for the first time by lentiviral transduction of GFP-progerin, which also resulted in impaired repair of IR-induced DSBs, and which correlated with abnormal nuclear morphology. Farnesyl transferase inhibitor (FTI) treatment improved the repair of IR-induced DSBs, but only in HGPS cells whose nuclear morphology was also normalized. Interestingly, FTI treatment did not result in a statistically significant reduction in the higher steady-state number of DSBs. We also report a delay in localization of phospho-NBS1 and MRE11, MRN complex repair factors necessary for homologous recombination (HR) repair, to DSBs in HGPS cells. Our results demonstrate a correlation between nuclear structural abnormalities and the DSB repair defect, suggesting a mechanistic link that may involve delayed repair factor localization to DNA damage. Further, our results show that similar to other HGPS phenotypes, FTI treatment has a beneficial effect on DSB repair.

  15. Defective DSB repair correlates with abnormal nuclear morphology and is improved with FTI treatment in Hutchinson-Gilford progeria syndrome fibroblasts.

    PubMed

    Constantinescu, Dan; Csoka, Antonei B; Navara, Christopher S; Schatten, Gerald P

    2010-10-15

    Impaired DSB repair has been implicated as a molecular mechanism contributing to the accelerating aging phenotype in Hutchinson-Gilford progeria syndrome (HGPS), but neither the extent nor the cause of the repair deficiency has been fully elucidated. Here we perform a quantitative analysis of the steady-state number of DSBs and the repair kinetics of ionizing radiation (IR)-induced DSBs in HGPS cells. We report an elevated steady-state number of DSBs and impaired repair of IR-induced DSBs, both of which correlated strongly with abnormal nuclear morphology. We recreated the HGPS cellular phenotype in human coronary artery endothelial cells for the first time by lentiviral transduction of GFP-progerin, which also resulted in impaired repair of IR-induced DSBs, and which correlated with abnormal nuclear morphology. Farnesyl transferase inhibitor (FTI) treatment improved the repair of IR-induced DSBs, but only in HGPS cells whose nuclear morphology was also normalized. Interestingly, FTI treatment did not result in a statistically significant reduction in the higher steady-state number of DSBs. We also report a delay in localization of phospho-NBS1 and MRE11, MRN complex repair factors necessary for homologous recombination (HR) repair, to DSBs in HGPS cells. Our results demonstrate a correlation between nuclear structural abnormalities and the DSB repair defect, suggesting a mechanistic link that may involve delayed repair factor localization to DNA damage. Further, our results show that similar to other HGPS phenotypes, FTI treatment has a beneficial effect on DSB repair.

  16. Renal Endothelial Dysfunction in Diabetic Nephropathy

    PubMed Central

    Cheng, Huifang; Harris, Raymond C.

    2015-01-01

    Endothelial dysfunction has been posited to play an important role in the pathogenesis of diabetic nephropathy (DN). Due to the heterogeneity of endothelial cells (ECs), it is difficult to generalize about endothelial responses to diabetic stimuli. At present, there are limited techniques fordirectly measuring EC function in vivo, so diagnosis of endothelial disorders still largely depends on indirect assessment of mediators arising from EC injury. In the kidney microcirculation, both afferent and efferent arteries, arterioles and glomerular endothelial cells (GEnC) have all been implicated as targets of diabetic injury. Both hyperglycemia per se, as well as the metabolic consequences of glucose dysregulation, are thought to lead to endothelial cell dysfunction. In this regard, endothelial nitric oxide synthase (eNOS) plays a central role in EC dysfunction. Impaired eNOS activity can occur at numerous levels, including enzyme uncoupling, post-translational modifications, internalization and decreased expression. Reduced nitric oxide (NO) bioavailability exacerbates oxidative stress, further promoting endothelial dysfunction and injury. The injured ECs may then function as active signal transducers of metabolic, hemodynamic and inflammatory factors that modify the function and morphology of the vessel wall and interact with adjacent cells, which may activate a cascade of inflammatory and proliferative and profibrotic responses in progressive DN. Both pharmacological approaches and potential regenerative therapies hold promise for restoration of impaired endothelial cells in diabetic nephropathy. PMID:24720460

  17. Molecular mechanisms that control endothelial cell contacts.

    PubMed

    Vestweber, D

    2000-02-01

    Endothelial cell contacts control the permeability of the blood vessel wall. This allows the endothelium to form a barrier for solutes, macromolecules, and leukocytes between the vessel lumen and the interstitial space. Loss of this barrier function in pathophysiological situations can lead to extracellular oedema. The ability of leukocytes to enter tissue at sites of inflammation is dependent on molecular mechanisms that allow leukocytes to adhere to the endothelium and to migrate through the endothelial cell layer and the underlying basal lamina. It is a commonly accepted working hypothesis that inter-endothelial cell contacts are actively opened and closed during this process. Angiogenesis is another important process that requires well-controlled regulation of inter-endothelial cell contacts. The formation of new blood vessels by sprouting from pre-existing vessels depends on the loosening of established endothelial cell contacts and the migration of endothelial cells that form the outgrowing sprouts. This review focuses on the molecular composition of endothelial cell surface proteins and proteins of the cytoskeletal undercoat of the plasma membrane at sites of inter-endothelial cell contacts and discusses the current knowledge about the potential role of such molecules in the regulation of endothelial cell contacts. PMID:10685062

  18. Progenitor endothelial cell involvement in Alzheimer's disease

    SciTech Connect

    Budinger, Thomas F.

    2003-05-01

    There is compelling evidence that endothelial cells of the brain and periphery are dysfunctional in Alzheimer's Disease. There is evidence for a fundamental defect in, or abnormal aging of, endothelial progenitor cells in atherosclerosis. The possibility that endothelial cell defects are a primary cause for Alzheimer's Disease or other dementias can be researched by molecular and cell biology studies as well as cell trafficking studies using recently demonstrated molecular imaging methods. The evidence for abnormal endothelial function and the methods to explore this hypothesis are presented.

  19. Endothelial cells in health and disease.

    PubMed

    Eckers, Anna; Haendeler, Judith

    2015-05-10

    According to the World Health Organization, from 2014, cardiovascular diseases (CVD) are the number one cause of death worldwide. One of the key players in maintaining proper cardiovascular function is the endothelium, the inner layer of all blood vessels. This monolayer of cells on one hand serves as a barrier between blood and the surrounding tissue and on the other hand regulates many aspects of vessel function. Therefore, it is not surprising that interventions reducing the risk for CVD improve endothelial function. There is a clear correlation between endothelial dysfunction, in which the endothelial homeostasis is disturbed, and the development and progression of many CVD. Thus, the development of diagnostic tools for early detection of disturbances in endothelial homeostasis or interventions aimed at improving endothelial function after insults require a comprehensive knowledge not only of the cellular reactions to the positive or negative stimuli but also of the molecular mechanisms relaying these responses. Thus, this Forum on "endothelial cells in health and disease" focuses on key molecules and processes intimately involved in endothelial cell function and covers areas from endothelial nitric oxide synthase-dependent processes, over the group of Phox-Bem1 domain proteins, cytochrome P450 epoxygenase-derived metabolites, and pre-mRNA splicing to microRNAs. Finally, one has to conclude that keeping endothelial homeostasis is the central key for a healthy long life of the human individual.

  20. High density lipoproteins and endothelial functions: mechanistic insights and alterations in cardiovascular disease.

    PubMed

    Riwanto, Meliana; Landmesser, Ulf

    2013-12-01

    Prospective population studies in the primary prevention setting have shown that reduced plasma levels of HDL cholesterol are associated with an increased risk of coronary disease and myocardial infarction. Experimental and translational studies have further revealed several potential anti-atherogenic effects of HDL, including protective effects on endothelial cell functions. HDL has been suggested to protect endothelial cell functions by prevention of oxidation of LDL and its adverse endothelial effects. Moreover, HDL from healthy subjects can directly stimulate endothelial cell production of nitric oxide and anti-inflammatory, anti-apoptotic, and anti-thrombotic effects as well as endothelial repair processes. However, several recent clinical trials using HDL cholesterol-raising agents, such as torcetrapib, dalcetrapib, and niacin, did not demonstrate a significant reduction of cardiovascular events in patients with coronary disease. Of note, growing evidence suggests that the vascular effects of HDL can be highly heterogeneous and vasoprotective properties of HDL are altered in patients with coronary disease. Characterization of underlying mechanisms and understanding of the clinical relevance of this "HDL dysfunction" is currently an active field of cardiovascular research. Notably, in some recent studies no clear association of higher HDL cholesterol levels with a reduced risk of cardiovascular events was observed in patients with already established coronary disease. A greater understanding of mechanisms of action of HDL and its altered vascular effects is therefore critical within the context of HDL-targeted therapies. In this review, we will address different effects of HDL on endothelial cell functions potentially relevant to atherosclerotic vascular disease and explore molecular mechanisms leading to "dysfunctional HDL".

  1. Platelets are relevant mediators of renal injury induced by primary endothelial lesions.

    PubMed

    Schwarzenberger, Claudia; Sradnick, Jan; Lerea, Kenneth M; Goligorsky, Michael S; Nieswandt, Bernhard; Hugo, Christian P M; Hohenstein, Bernd

    2015-06-01

    Several studies have suggested a prominent (pro)inflammatory and harmful role of platelets in renal disease, and newer work has also demonstrated platelet release of proangiogenic factors. In the present study, we investigated the role of platelets in a mouse model of selective endothelial cell injury using either platelet depletion or the pharmacological P2Y12 receptor blocker clopidogrel as an interventional strategy. The concanavalin A/anti-concanavalin A model was induced in left kidneys of C57bl/6J wild-type mice after initial platelet depletion or platelet-inhibiting therapy using clopidogrel. FACS analysis of glycoprotein IIb/IIIa/P-selectin double-positive platelets and platelet-derived microparticles demonstrated relevant platelet activation after the induction of selective endothelial injury in mice. Enhanced platelet activation persisted for 5 days after disease induction and was accompanied by increased amounts of circulating platelet-derived microparticles as potential mediators of a prolonged procoagulant state. By immunohistochemistry, we detected significantly reduced glomerular injury in platelet-depleted mice compared with control mice. In parallel, we also saw reduced endothelial loss and a consequently reduced repair response as indicated by diminished proliferative activity. The P2Y12 receptor blocker clopidogrel demonstrated efficacy in limiting platelet activation and subsequent endothelial injury in this mouse model of renal microvascular injury. In conclusion, platelets are relevant mediators of renal injury induced by primary endothelial lesions early on, as demonstrated by platelet depletion as well as platelet inhibition via the P2Y12 receptor. While strategies to prevent platelet-endothelial interactions have shown protective effects, the contribution of platelets during renal regeneration remains unknown.

  2. Platelets are relevant mediators of renal injury induced by primary endothelial lesions

    PubMed Central

    Schwarzenberger, Claudia; Sradnick, Jan; Lerea, Kenneth M.; Goligorsky, Michael S.; Nieswandt, Bernhard; Hugo, Christian P. M.

    2015-01-01

    Several studies have suggested a prominent (pro)inflammatory and harmful role of platelets in renal disease, and newer work has also demonstrated platelet release of proangiogenic factors. In the present study, we investigated the role of platelets in a mouse model of selective endothelial cell injury using either platelet depletion or the pharmacological P2Y12 receptor blocker clopidogrel as an interventional strategy. The concanavalin A/anti-concanavalin A model was induced in left kidneys of C57bl/6J wild-type mice after initial platelet depletion or platelet-inhibiting therapy using clopidogrel. FACS analysis of glycoprotein IIb/IIIa/P-selectin double-positive platelets and platelet-derived microparticles demonstrated relevant platelet activation after the induction of selective endothelial injury in mice. Enhanced platelet activation persisted for 5 days after disease induction and was accompanied by increased amounts of circulating platelet-derived microparticles as potential mediators of a prolonged procoagulant state. By immunohistochemistry, we detected significantly reduced glomerular injury in platelet-depleted mice compared with control mice. In parallel, we also saw reduced endothelial loss and a consequently reduced repair response as indicated by diminished proliferative activity. The P2Y12 receptor blocker clopidogrel demonstrated efficacy in limiting platelet activation and subsequent endothelial injury in this mouse model of renal microvascular injury. In conclusion, platelets are relevant mediators of renal injury induced by primary endothelial lesions early on, as demonstrated by platelet depletion as well as platelet inhibition via the P2Y12 receptor. While strategies to prevent platelet-endothelial interactions have shown protective effects, the contribution of platelets during renal regeneration remains unknown. PMID:25834071

  3. Endovascular abdominal aortic aneurysm repair

    PubMed Central

    Norwood, M G A; Lloyd, G M; Bown, M J; Fishwick, G; London, N J; Sayers, R D

    2007-01-01

    The operative mortality following conventional abdominal aortic aneurysm (AAA) repair has not fallen significantly over the past two decades. Since its inception in 1991, endovascular aneurysm repair (EVAR) has provided an alternative to open AAA repair and perhaps an opportunity to improve operative mortality. Two recent large randomised trials have demonstrated the short and medium term benefit of EVAR over open AAA repair, although data on the long term efficacy of the technique are still lacking. This review aimed at providing an overview of EVAR and a discussion of the potential benefits and current limitations of the technique. PMID:17267674

  4. Influence of different stent materials on endothelialization in vitro.

    PubMed

    Nikolaychik, V; Sahota, H; Keelan, M H; Chawla, P S; Hernandes, I; Ferguson, J J; Kipshidze, N

    1999-07-01

    The objective of our study was to investigate the influence of different stent materials on endothelialization in vitro. Using the non-destructive Alamar Blue assay and scanning electron microscopy, we compared long-term growth and morphology of vascular cells on disks of three prospective stent materials, i.e., 316 L stainless steel, 18 K, and 24 K gold. Our results demonstrate superior human EC proliferative capacity on gold surfaces compared to that on 316 L stainless steel. Thus, both the hyperplasia and thrombotic complications which often follow stenting might be minimized by employing gold stents, which have a greater capacity than steel in supporting a functional neo-endothelium. PMID:10745563

  5. 49 CFR 193.2617 - Repairs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repairs. 193.2617 Section 193.2617 Transportation...: FEDERAL SAFETY STANDARDS Maintenance § 193.2617 Repairs. (a) Repair work on components must be performed... repaired. (b) For repairs made while a component is operating, each operator shall include in...

  6. The regulatory mechanism of Hsp90{alpha} secretion from endothelial cells and its role in angiogenesis during wound healing

    SciTech Connect

    Song, Xiaomin; Luo, Yongzhang

    2010-07-16

    Research highlights: {yields} Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90{alpha} secretion from endothelial cells. {yields} Secreted Hsp90{alpha} localizes on the leading edge of activated endothelial cells. {yields} Secreted Hsp90{alpha} promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90{alpha} (Hsp90{alpha}) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90{alpha} can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation and migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90{alpha} from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90{alpha} in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90{alpha} but not Hsp90{beta} is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90{alpha} localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90{alpha} neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90{alpha} localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90{alpha} can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90{alpha} as a stimulator for wound repair.

  7. Influence of the oxygen microenvironment on the proangiogenic potential of human endothelial colony forming cells.

    PubMed

    Decaris, Martin L; Lee, Chang I; Yoder, Mervin C; Tarantal, Alice F; Leach, J Kent

    2009-01-01

    Therapeutic angiogenesis is a promising strategy to promote the formation of new or collateral vessels for tissue regeneration and repair. Since changes in tissue oxygen concentrations are known to stimulate numerous cell functions, these studies have focused on the oxygen microenvironment and its role on the angiogenic potential of endothelial cells. We analyzed the proangiogenic potential of human endothelial colony-forming cells (hECFCs), a highly proliferative population of circulating endothelial progenitor cells, and compared outcomes to human dermal microvascular cells (HMVECs) under oxygen tensions ranging from 1% to 21% O2, representative of ischemic or healthy tissues and standard culture conditions. Compared to HMVECs, hECFCs (1) exhibited significantly greater proliferation in both ischemic conditions and ambient air; (2) demonstrated increased migration compared to HMVECs when exposed to chemotactic gradients in reduced oxygen; and (3) exhibited comparable or superior proangiogenic potential in reduced oxygen conditions when assessed using a vessel-forming assay. These data demonstrate that the angiogenic potential of both endothelial populations is influenced by the local oxygen microenvironment. However, hECFCs exhibit a robust angiogenic potential in oxygen conditions representative of physiologic, ischemic, or ambient air conditions, and these findings suggest that hECFCs may be a superior cell source for use in cell-based approaches for the neovascularization of ischemic or engineered tissues.

  8. Peptide-modified PELCL electrospun membranes for regulation of vascular endothelial cells.

    PubMed

    Zhou, Fang; Jia, Xiaoling; Yang, Yang; Yang, Qingmao; Gao, Chao; Zhao, Yunhui; Fan, Yubo; Yuan, Xiaoyan

    2016-11-01

    The efficiency of biomaterials used in small vascular repair depends greatly on their ability to interact with vascular endothelial cells (VECs). Rapid endothelialization of the vascular grafts is a promising way to prevent thrombosis and intimal hyperplasia. In this work, modification of electrospun membranes of poly(ethylene glycol)-b-poly(l-lactide-co-ε-caprolactone) (PELCL) by three different peptides for regulation of VECs were studied in order to obtain ideal bioactive biomaterials as small diameter vascular grafts. QK (a mimetic peptide to vascular endothelial growth factor), Arg-Glu-Asp-Val (REDV, a specific adhesive peptide to VECs) and Val-Ala-Pro-Gly (VAPG, a specific adhesive peptide to vascular smooth muscle cells) were investigated. Surface properties of the modified membranes and the response of VECs were verified. It was found that protein adsorption and platelet adhesion were effectively suppressed with the introduction of QK, REDV or VAPG peptides on the PELCL electrospun membranes. Both QK- and REDV-modified electrospun membranes could accelerate the proliferation of VECs in the first 9days, and the QK-modified electrospun membrane promoted cell proliferation more significantly than the REDV-modified one. The REDV-modified PELCL membrane was the most favorable for VECs adhesion than QK- and VAPG-modified membranes. It was suggested that QK- or REDV-modified PELCL electrospun membranes may have great potential applications in cardiovascular biomaterials for rapid endothelialization in situ. PMID:27524062

  9. Peptide-modified PELCL electrospun membranes for regulation of vascular endothelial cells.

    PubMed

    Zhou, Fang; Jia, Xiaoling; Yang, Yang; Yang, Qingmao; Gao, Chao; Zhao, Yunhui; Fan, Yubo; Yuan, Xiaoyan

    2016-11-01

    The efficiency of biomaterials used in small vascular repair depends greatly on their ability to interact with vascular endothelial cells (VECs). Rapid endothelialization of the vascular grafts is a promising way to prevent thrombosis and intimal hyperplasia. In this work, modification of electrospun membranes of poly(ethylene glycol)-b-poly(l-lactide-co-ε-caprolactone) (PELCL) by three different peptides for regulation of VECs were studied in order to obtain ideal bioactive biomaterials as small diameter vascular grafts. QK (a mimetic peptide to vascular endothelial growth factor), Arg-Glu-Asp-Val (REDV, a specific adhesive peptide to VECs) and Val-Ala-Pro-Gly (VAPG, a specific adhesive peptide to vascular smooth muscle cells) were investigated. Surface properties of the modified membranes and the response of VECs were verified. It was found that protein adsorption and platelet adhesion were effectively suppressed with the introduction of QK, REDV or VAPG peptides on the PELCL electrospun membranes. Both QK- and REDV-modified electrospun membranes could accelerate the proliferation of VECs in the first 9days, and the QK-modified electrospun membrane promoted cell proliferation more significantly than the REDV-modified one. The REDV-modified PELCL membrane was the most favorable for VECs adhesion than QK- and VAPG-modified membranes. It was suggested that QK- or REDV-modified PELCL electrospun membranes may have great potential applications in cardiovascular biomaterials for rapid endothelialization in situ.

  10. Existence of Neural Crest-Derived Progenitor Cells in Normal and Fuchs Endothelial Dystrophy Corneal Endothelium.

    PubMed

    Katikireddy, Kishore Reddy; Schmedt, Thore; Price, Marianne O; Price, Francis W; Jurkunas, Ula V

    2016-10-01

    Human corneal endothelial cells are derived from neural crest and because of postmitotic arrest lack competence to repair cell loss from trauma, aging, and degenerative disorders such as Fuchs endothelial corneal dystrophy (FECD). Herein, we identified a rapidly proliferating subpopulation of cells from the corneal endothelium of adult normal and FECD donors that exhibited features of neural crest-derived progenitor (NCDP) cells by showing absence of senescence with passaging, propensity to form spheres, and increased colony forming efficacy compared with the primary cells. The collective expression of stem cell-related genes SOX2, OCT4, LGR5, TP63 (p63), as well as neural crest marker genes PSIP1 (p75(NTR)), PAX3, SOX9, AP2B1 (AP-2β), and NES, generated a phenotypic footprint of endothelial NCDPs. NCDPs displayed multipotency by differentiating into microtubule-associated protein 2, β-III tubulin, and glial fibrillary acidic protein positive neurons and into p75(NTR)-positive human corneal endothelial cells that exhibited transendothelial resistance of functional endothelium. In conclusion, we found that mitotically incompetent ocular tissue cells contain adult NCDPs that exhibit a profile of transcription factors regulating multipotency and neural crest progenitor characteristics. Identification of normal NCDPs in FECD-affected endothelium holds promise for potential autologous cell therapies. PMID:27639969

  11. TNFα-Damaged-HUVECs Microparticles Modify Endothelial Progenitor Cell Functional Activity

    PubMed Central

    Luna, Carlos; Carmona, Andrés; Alique, Matilde; Carracedo, Julia; Ramirez, Rafael

    2015-01-01

    Endothelial progenitor cells (EPCs) have an important role in the maintenance of vascular integrity and homeostasis. While there are many studies that explain EPCs mechanisms action, there are few studies that demonstrate how they interact with other emerging physiological elements such as Endothelial Microparticles (EMPs). EMPs are membranous structures with a size between 100 and 1000 nm that act as molecular information transporter in biological systems and are known as an important elements in develop different pathologies; moreover a lot of works explains that are novel biomarkers. To elucidate these interactions, we proposed an in vitro model of endothelial damage mediated by TNFalpha, in which damaged EMPs and EPCs are in contact to assess EPCs functional effects. We have observed that damaged EMPs can modulate several EPCs classic factors as colony forming units (CFUs), contribution to repair a physically damaged endothelium (wound healing), binding to mature endothelium, and co-adjuvants to the formation of new vessels in vitro (angiogenesis). All of these in a dose-dependent manner. Damaged EMPs at a concentration of 103 MPs/ml have an activating effect of these capabilities, while at concentrations of 105 MPs/ml these effects are attenuated or reduced. This in vitro model helps explain that in diseases where there is an imbalance between these two elements (EPCs and damaged EMPs), the key cellular elements in the regeneration and maintenance of vascular homeostasis (EPCs) are not fully functional, and could explain, at least in part, endothelial dysfunction associated in various pathologies. PMID:26733886

  12. Therapeutic Benefit of Bone Marrow–Derived Endothelial Progenitor Cell Transplantation after Experimental Aneurysm Embolization with Coil in Rats

    PubMed Central

    Li, Qianyun; Huang, Jun; Chen, Xi; Chen, Xiaoyan; Zhang, Jun; Wang, Yongting; Yang, Guo-Yuan; Zhu, Wei

    2014-01-01

    Aneurysm embolization with coil is now widely used clinically. However, the recurrence of aneurysms after embolization has always plagued neurosurgeons because the endothelial layer of the aneurysm neck loses its integrity after being embolized by coil. Bone marrow–derived endothelial progenitor cells (BM-EPCs) could be incorporated into injured endothelium and differentiate into mature endothelial cells during vascular repairing processes. The aim of our study is to explore the effects of BM-EPCs on aneurysm repairing and remodeling in a rat embolization model of abdominal aortic aneurysm. BM-EPC proliferation, migration and tube formation were not affected by super-paramagnetic iron oxide nanoparticle (SPIO) labeling compared to the controls (p>0.05). The number of SPIO-labeled cells greatly increased in EPC transplanted rats compared to that of phosphate buffered saline treated rats. SPIO-labeled EPC (SPIO-EPC) are mainly located in the aneurysm neck and surrounded by fibrous tissue. A histology study showed that the aneurysm orifice was closed with neointima and the aneurysm was filled with newly formed fibrous tissue. The SPIO-EPC accumulated in the aneurysm neck, which accelerated focal fibrous tissue remodeling, suggesting that BM-EPCs play a crucial role in repairing and remodeling the aneurysm neck orifice. PMID:24587209

  13. Stem cells: potential and challenges for kidney repair

    PubMed Central

    Herrera, Marcela

    2013-01-01

    Renal damage resulting from acute and chronic kidney injury poses an important problem to public health. Currently, patients with end-stage renal disease rely solely on kidney transplantation or dialysis for survival. Emerging therapies aiming to prevent and reverse kidney damage are thus in urgent need. Although the kidney was initially thought to lack the capacity for self-repair, several studies have indicated that this might not be the case; progenitor and stem cells appear to play important roles in kidney repair under various pathological conditions. In this review, we summarize recent findings on the role of progenitor/stem cells on kidney repair as well as discuss their potential as a therapeutic approach for kidney diseases. PMID:24197069

  14. Pectoralis Major Tendon Repair

    PubMed Central

    Cordasco, Frank A.; Degen, Ryan; Mahony, Gregory Thomas; Tsouris, Nicholas

    2016-01-01

    Objectives: Systematic reviews of the literature have identified 365 reported cases of Pectoralis Major Tendon (PMT) injuries. While surgical treatment has demonstrated improved outcomes compared to non-operative treatment, there is still relatively limited data on the functional outcome, return to sport and need for 2nd surgery in athletes following PMT repair. This study comprises the largest series of athletes following PMT repair reported to date. The Objective is to report on the functional outcomes, return to sport and need for 2nd surgery in a consecutive series of PMT tears. Methods: From 2009, 81 patients with PMT tears were enrolled in this prospective series. Baseline evaluation included patient demographics, mechanism of injury, physical examination and PMT specific MRI for confirmation of the diagnosis and analysis of the extent of injury. Each patient underwent surgical repair by the senior author utilizing a previously published surgical technique. Patients were then followed at 2 weeks, 6 weeks, 3 months and 6 months and further follow-up was conducted annually thereafter with functional outcome scores and adduction strength testing. The return to sport and incidence of 2nd surgery data were recorded. This study includes the first 40 athletes to reach the 2-year post-operative period. Results: All athletes were male, with an average age of 34.4 years (range 23-59). The patient cohort consisted of 4 professional NFL players and 36 recreational athletes. Average follow-up duration was 2.5 years (range 2 - 6.0 years). The most common mechanisms of injury occurred during the bench press (n=26) and contact sport participation (n=14). Sixteen injuries were complete avulsions involving both the clavicular and sternocostal heads, while 24 were isolated sternocostal head avulsions. Average pre-injury bench press of 396 lbs (range 170-500 lbs) was restored to 241 lbs post-operatively (range 140-550 lbs). Single Assessment Numeric Evaluation (SANE) scores

  15. CXCR2 modulates bone marrow vascular repair and haematopoietic recovery post-transplant.

    PubMed

    Hale, Sarah J M; Hale, Ashley B H; Zhang, Youyi; Sweeney, Dominic; Fisher, Nita; van der Garde, Mark; Grabowska, Rita; Pepperell, Emma; Channon, Keith; Martin-Rendon, Enca; Watt, Suzanne M

    2015-05-01

    Murine models of bone marrow transplantation show that pre-conditioning regimens affect the integrity of the bone marrow endothelium and that the repair of this vascular niche is an essential pre-requisite for successful haematopoietic stem and progenitor cell engraftment. Little is known about the angiogenic pathways that play a role in the repair of the human bone marrow vascular niche. We therefore established an in vitro humanized model, composed of bone marrow stromal and endothelial cells and have identified several pro-angiogenic factors, VEGFA, ANGPT1, CXCL8 and CXCL16, produced by the stromal component of this niche. We demonstrate for the first time that addition of CXCL8 or inhibition of its receptor, CXCR2, modulates blood vessel formation in our bone marrow endothelial niche model. Compared to wild type, Cxcr2(-/-) mice displayed a reduction in bone marrow cellularity and delayed platelet and leucocyte recovery following myeloablation and bone marrow transplantation. The delay in bone marrow recovery correlated with impaired bone marrow vascular repair. Taken together, our data demonstrate that CXCR2 regulates bone marrow blood vessel repair/regeneration and haematopoietic recovery, and clinically may be a therapeutic target for improving bone marrow transplantation.

  16. Targeting of the pulmonary capillary vascular niche promotes lung alveolar repair and ameliorates fibrosis.

    PubMed

    Cao, Zhongwei; Lis, Raphael; Ginsberg, Michael; Chavez, Deebly; Shido, Koji; Rabbany, Sina Y; Fong, Guo-Hua; Sakmar, Thomas P; Rafii, Shahin; Ding, Bi-Sen

    2016-02-01

    Although the lung can undergo self-repair after injury, fibrosis in chronically injured or diseased lungs can occur at the expense of regeneration. Here we study how a hematopoietic-vascular niche regulates alveolar repair and lung fibrosis. Using intratracheal injection of bleomycin or hydrochloric acid in mice, we show that repetitive lung injury activates pulmonary capillary endothelial cells (PCECs) and perivascular macrophages, impeding alveolar repair and promoting fibrosis. Whereas the chemokine receptor CXCR7, expressed on PCECs, acts to prevent epithelial damage and ameliorate fibrosis after a single round of treatment with bleomycin or hydrochloric acid, repeated injury leads to suppression of CXCR7 expression and recruitment of vascular endothelial growth factor receptor 1 (VEGFR1)-expressing perivascular macrophages. This recruitment stimulates Wnt/β-catenin-dependent persistent upregulation of the Notch ligand Jagged1 (encoded by Jag1) in PCECs, which in turn stimulates exuberant Notch signaling in perivascular fibroblasts and enhances fibrosis. Administration of a CXCR7 agonist or PCEC-targeted Jag1 shRNA after lung injury promotes alveolar repair and reduces fibrosis. Thus, targeting of a maladapted hematopoietic-vascular niche, in which macrophages, PCECs and perivascular fibroblasts interact, may help to develop therapy to spur lung regeneration and alleviate fibrosis.

  17. Comparison of endothelial evaluation techniques.

    PubMed

    Langston, R H; Roisman, T S

    1981-01-01

    Comparative evaluation of the corneal endothelium with the Heyer-Schulte specular photomicroscope, the McIntyre CEB reticle affixed to a slitlamp, and a slitlamp alone found the reticle-slitlamp combination to give results within a 10% average of endothelial cell counts determined with the specular microscope. The reticle also compared favorably in time and cost savings. All three methods of corneal evaluation were effective for observation of polymegathism. Because of its lower magnification, the slitlamp without the reticle was best suited for evaluation of cornea guttata. PMID:7287565

  18. Nuclear p120 catenin unlocks mitotic block of contact-inhibited human corneal endothelial monolayers without disrupting adherent junctions

    PubMed Central

    Zhu, Ying-Ting; Chen, Hung-Chi; Chen, Szu-Yu; Tseng, Scheffer C. G.

    2012-01-01

    Summary Contact inhibition ubiquitously exists in non-transformed cells that are in contact with neighboring cells. This phenomenon explains the poor regenerative capacity of in vivo human corneal endothelial cells during aging, injury and surgery. This study demonstrated that the conventional approach of expanding human corneal endothelial cells by disrupting contact inhibition with EDTA followed by bFGF activated canonical Wnt signaling and lost the normal phenotype to endothelial–mesenchymal transition, especially if TGFβ1 was added. By contrast, siRNA against p120 catenin (CTNND1) also uniquely promoted proliferation of the endothelial cells by activating trafficking of p120 catenin to the nucleus, thus relieving repression by nuclear Kaiso. This nuclear p120-catenin–Kaiso signaling is associated with activation of RhoA–ROCK signaling, destabilization of microtubules and inhibition of Hippo signaling, but not with activation of Wnt–β-catenin signaling. Consequently, proliferating human corneal endothelial cells maintained a hexagonal shape, with junctional expression of N-cadherin, ZO-1 and Na+/K+-ATPase. Further expansion of human corneal endothelial monolayers with a normal phenotype and a higher density was possible by prolonging treatment with p120 catenin siRNA followed by its withdrawal. This new strategy of perturbing contact inhibition by selective activation of p120-catenin–Kaiso signaling without disrupting adherent junction could be used to engineer surgical grafts containing normal human corneal endothelial cells to meet a global corneal shortage and for endothelial keratoplasties. PMID:22505615

  19. Liver sinusoidal endothelial cells (LSECs) function and NAFLD; NO-based therapy targeted to the liver.

    PubMed

    Maslak, Edyta; Gregorius, Aleksandra; Chlopicki, Stefan

    2015-08-01

    Liver sinusoidal endothelial cells (LSECs) present unique, highly specialised endothelial cells in the body. Unlike the structure and function of typical, vascular endothelial cells, LSECs are comprised of fenestrations, display high endocytic capacity and play a prominent role in maintaining overall liver homeostasis. LSEC dysfunction has been regarded as a key event in multiple liver disorders; however, its role and diagnostic, prognostic and therapeutic significance in nonalcoholic fatty liver disease (NAFLD) is still neglected. The purpose of this review is to provide an overview of the importance of LSECs in NAFLD. Attention is focused on the LSECs-mediated NO-dependent mechanisms in NAFLD development. We briefly describe the unique, highly specialised phenotype of LSECs and consequences of LSEC dysfunction on function of hepatic stellate cells (HSC) and hepatocytes. The potential efficacy of liver selective NO donors against liver steatosis and novel treatment approaches to modulate LSECs-driven liver pathology including NAFLD are also highlighted.

  20. Industrial motor repair in the United States

    SciTech Connect

    Schueler, V.; Leistner, P.; Douglass, J.

    1994-09-01

    This report characterizes the motor repair industry in the United States; summarizes current motor repair and testing practice; and identifies barriers to energy motor repair practice and recommends strategies for overcoming those barriers.

  1. Membrane Repair: Mechanisms and Pathophysiology

    PubMed Central

    Cooper, Sandra T.; McNeil, Paul L.

    2015-01-01

    Eukaryotic cells have been confronted throughout their evolution with potentially lethal plasma membrane injuries, including those caused by osmotic stress, by infection from bacterial toxins and parasites, and by mechanical and ischemic stress. The wounded cell can survive if a rapid repair response is mounted that restores boundary integrity. Calcium has been identified as the key trigger to activate an effective membrane repair response that utilizes exocytosis and endocytosis to repair a membrane tear, or remove a membrane pore. We here review what is known about the cellular and molecular mechanisms of membrane repair, with particular emphasis on the relevance of repair as it relates to disease pathologies. Collective evidence reveals membrane repair employs primitive yet robust molecular machinery, such as vesicle fusion and contractile rings, processes evolutionarily honed for simplicity and success. Yet to be fully understood is whether core membrane repair machinery exists in all cells, or whether evolutionary adaptation has resulted in multiple compensatory repair pathways that specialize in different tissues and cells within our body. PMID:26336031

  2. Cobbler's Technique for Iridodialysis Repair

    PubMed Central

    Pandav, Surinder Singh; Gupta, Parul Chawla; Singh, Rishi Raj; Das, Kalpita; Kaushik, Sushmita; Raj, Srishti; Ram, Jagat

    2016-01-01

    We describe a novel “Cobbler's technique” for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The “Cobbler's technique” allows a maximally functional and cosmetic result for iridodialysis. PMID:26957855

  3. Cobbler's Technique for Iridodialysis Repair.

    PubMed

    Pandav, Surinder Singh; Gupta, Parul Chawla; Singh, Rishi Raj; Das, Kalpita; Kaushik, Sushmita; Raj, Srishti; Ram, Jagat

    2016-01-01

    We describe a novel "Cobbler's technique" for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The "Cobbler's technique" allows a maximally functional and cosmetic result for iridodialysis. PMID:26957855

  4. Laparoscopic paracolostomy hernia mesh repair.

    PubMed

    Virzí, Giuseppe; Giuseppe, Virzí; Scaravilli, Francesco; Francesco, Scaravilli; Ragazzi, Salvatore; Salvatore, Ragazzi; Piazza, Diego; Diego, Piazza

    2007-12-01

    Paracolostomy hernia is a common occurrence, representing a late complication of stoma surgery. Different surgical techniques have been proposed to repair the wall defect, but the lowest recurrence rates are associated with the use of mesh. We present the case report of a patient in which laparoscopic paracolostomy hernia mesh repair has been successfully performed. PMID:18097321

  5. Major Appliance Repair. Teacher Edition.

    ERIC Educational Resources Information Center

    Smreker, Eugene; Calvert, King

    This module is a comprehensive text on basic appliance repair, designed to prepare students for entry-level jobs in this growing field. Ensuring a firm grounding in electrical knowledge, the module contains 13 instructional units that cover the following topics: (1) major appliance repair orientation; (2) safety and first aid; (3) fundamentals of…

  6. Instructional Guide for Autobody Repair.

    ERIC Educational Resources Information Center

    Virginia Polytechnic Inst. and State Univ., Blacksburg. Dept. of Education.

    The curriculum guide was developed to serve as a statewide model for Virginia auto body repair programs. The guide is designed to 1,080 hours of instruction in eleven blocks: orientation, introduction, welding and cutting, techniques of shaping metal, body filler and fiberglass repairs, body and frame, removing and replacing damaged parts, basic…

  7. Communication Repair and Response Classes

    ERIC Educational Resources Information Center

    Meadan, Hedda; Halle, James W.

    2004-01-01

    A communicative repair has been defined as the ability to persist in communication and to modify, repeat, or revise a signal when the initial communication attempt failed. From an operant perspective, initial communicative acts and communicative repairs can be considered members of a response class in which each response produces the same outcome.…

  8. Pipe inspection and repair system

    NASA Technical Reports Server (NTRS)

    Schempf, Hagen (Inventor); Mutschler, Edward (Inventor); Chemel, Brian (Inventor); Boehmke, Scott (Inventor); Crowley, William (Inventor)

    2004-01-01

    A multi-module pipe inspection and repair device. The device includes a base module, a camera module, a sensor module, an MFL module, a brush module, a patch set/test module, and a marker module. Each of the modules may be interconnected to construct one of an inspection device, a preparation device, a marking device, and a repair device.

  9. Stimulation of tendon repair: mechanical loading, GDFs and platelets. A mini-review

    PubMed Central

    2007-01-01

    The repair of subcutaneous tendon ruptures can be stimulated by a single application of one of several growth factors [e.g. platelet-derived growth factor (PDGF), transforming growth factor (TGF)-beta, insulin-like growth factor (IGF)-1, vascular endothelial growth factor (VEGF), bone morphogenetic proteins (BMPs) like growth differentiation factor (GDF)-5, -6, -7] or by a thrombocyte concentrate (PRP). The response to these measures is dependent on the mechanical microenvironment, which is crucial for repair. So far, almost all research has been limited to rodent models, mostly using the rat Achilles tendon. Ruptured human Achilles tendons appear to be mechanically loaded in spite of immobilisation. This suggests that the mechanical microenvironment might be favourable for the clinical use of growth factors or platelets for this indication. New methods to quantitate human Achilles tendon repair have been developed. PMID:17583812

  10. Vascular endothelial dysfunction and pharmacological treatment

    PubMed Central

    Su, Jin Bo

    2015-01-01

    The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smoking, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide (NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease. PMID:26635921

  11. Vascular endothelial dysfunction and pharmacological treatment.

    PubMed

    Su, Jin Bo

    2015-11-26

    The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smoking, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide (NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease. PMID:26635921

  12. [Regeneration capacity of skeletal muscle].

    PubMed

    Wernig, A

    2003-07-01

    The organotypic stem cell of skeletal muscle has previously been known as satellite cell. They allow muscle fiber growth during ontogenesis, enable fiber hypertrophy and are responsible for the very efficient repair of muscle fibers. This efficient apparatus is to some degree counterbalanced by an enormous use of the satellite cell pool: fiber atrophy probably is accompanied by loss of myonuclei such that every reversal of atrophy is bound to use new myonuclei i.e. satellite cells. How often in life does this occur? Hard to say. Moreover, the potent repair capacity is challenged by an unexpected vulnerability of skeletal muscle fibers: Passive stretching of contracted muscles may cause multiple "microdamage," disruption of contractile elements or tiny areas of true necrosis (focal necrosis). How often does this happen? Well, for many of us at least once per year when we go up and down mountains during vacation time, followed by sour muscles. Others may decide to change his/her (locomotor) behaviour by severe onset of jogging; it may happen that they suffer kidney failure on Monday due to muscle microdamage and the transfer of myoproteins into the serum over weekend. Also 20 minutes of stepping up and down something like a chair will do: There is a remarkable increase in kreatin kinase and other muscle derived proteins which lasts for days and is bound to reflect some muscle damage. How about sportsmen and worker who repeatedly use their muscles in such a way? We don't have answers yet to most of these questions, but considerable amount of information has been collected over the last years both in animal and--less--in human. What is common in all cases of growth and repair is the proliferation of the satellite cells and their consequent incorporation and fusion with the parent fiber. This way focal damage is repaired often without visible reminders. We would run out of satellite cells were they not stem cells: After division one daughter remains a satellite cell

  13. Effects of implantation of three-dimensional engineered bone tissue with a vascular-like structure on repair of bone defects

    NASA Astrophysics Data System (ADS)

    Nishi, Masanori; Matsumoto, Rena; Dong, Jian; Uemura, Toshimasa

    2012-12-01

    Previously, to create an implantable bone tissue associated with blood vessels, we co-cultured rabbit bone marrow mesenchymal stem cells (MSCs) with MSC-derived endothelial cells (ECs) within a porous polylactic acid-based scaffold utilizing a rotating wall vessel (RWV) bioreactor. Here, this engineered tissue was orthotopically implanted into defects made in femurs of immunodeficient rats, and histological analysis were carried out to examine the repair of the damage and the formation of bone around the implant. The bone defects were better repaired in the implanted group than control group after 3 weeks. The results indicate that the engineered bone could repair bone defects.

  14. Endothelial Dysfunction in Type 2 Diabetes Mellitus.

    PubMed

    Dhananjayan, R; Koundinya, K S Srivani; Malati, T; Kutala, Vijay Kumar

    2016-10-01

    Endothelial dysfunction is an imbalance in the production of vasodilator factors and when this balance is disrupted, it predisposes the vasculature towards pro-thrombotic and pro-atherogenic effects. This results in vasoconstriction, leukocyte adherence, platelet activation, mitogenesis, pro-oxidation, impaired coagulation and nitric oxide production, vascular inflammation, atherosclerosis and thrombosis. Endothelial dysfunction is focussed as it is a potential contributor to the pathogenesis of vascular disease in diabetes mellitus. Under physiological conditions, there is a balanced release of endothelial-derived relaxing and contracting factors, but this delicate balance is altered in diabetes mellitus and atherosclerosis, thereby contributing to further progression of vascular and end-organ damage. This review focuses on endothelial dysfunction in atherosclerosis, insulin resistance, metabolic syndrome, oxidative stress associated with diabetes mellitus, markers and genetics that are implicated in endothelial dysfunction.

  15. Endothelial cell micropatterning: Methods, effects, and applications

    PubMed Central

    Anderson, Deirdre E.J.; Hinds, Monica T.

    2012-01-01

    The effects of flow on endothelial cells have been widely examined for the ability of fluid shear stress to alter cell morphology and function; however, the effects of endothelial cell morphology without flow have only recently been observed. An increase in lithographic techniques in cell culture spurred a corresponding increase in research aiming to confine cell morphology. These studies lead to a better understanding of how morphology and cytoskeletal configuration affect the structure and function of the cells. This review examines endothelial cell micropatterning research by exploring both the many alternative methods used to alter endothelial cell morphology and the resulting changes in cellular shape and phenotype. Micropatterning induced changes in endothelial cell proliferation, apoptosis, cytoskeletal organization, mechanical properties, and cell functionality. Finally, the ways these cellular manipulation techniques have been applied to biomedical engineering research, including angiogenesis, cell migration, and tissue engineering, is discussed. PMID:21761242

  16. Endothelial Dysfunction in Type 2 Diabetes Mellitus.

    PubMed

    Dhananjayan, R; Koundinya, K S Srivani; Malati, T; Kutala, Vijay Kumar

    2016-10-01

    Endothelial dysfunction is an imbalance in the production of vasodilator factors and when this balance is disrupted, it predisposes the vasculature towards pro-thrombotic and pro-atherogenic effects. This results in vasoconstriction, leukocyte adherence, platelet activation, mitogenesis, pro-oxidation, impaired coagulation and nitric oxide production, vascular inflammation, atherosclerosis and thrombosis. Endothelial dysfunction is focussed as it is a potential contributor to the pathogenesis of vascular disease in diabetes mellitus. Under physiological conditions, there is a balanced release of endothelial-derived relaxing and contracting factors, but this delicate balance is altered in diabetes mellitus and atherosclerosis, thereby contributing to further progression of vascular and end-organ damage. This review focuses on endothelial dysfunction in atherosclerosis, insulin resistance, metabolic syndrome, oxidative stress associated with diabetes mellitus, markers and genetics that are implicated in endothelial dysfunction. PMID:27605734

  17. Wound repair in Pocillopora.

    PubMed

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry Martin; Calderon-Aguilera, Luis Eduardo

    2016-09-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals. PMID:27397755

  18. Wound repair in Pocillopora

    USGS Publications Warehouse

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry M.; Calderon-Aguileraa, Luis Eduardo

    2016-01-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40 days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40 d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals.

  19. Wound repair in Pocillopora.

    PubMed

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry Martin; Calderon-Aguilera, Luis Eduardo

    2016-09-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals.

  20. TPS Inspection and Repair

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott

    2012-01-01

    Dr. Scott Parazynski provided a retrospective on the EVA tools and procedures efforts NASA went through in the aftermath of Columbia for the Shuttle Thermal Protection System (TPS) inspection and repair. He describes his role as the lead astronaut on this effort, and covered all of the Neutral Buoyancy Lab (NBL), KC 135 (reduced gravity aircraft), Precision Air Bearing Floor (PABF), vacuum chamber and 1 G testing that was done in order to develop the tools and techniques that were flown. Parazynski also discusses how the EVA community worked together to resolve a huge safety issue, and how his work in the spacesuit was critical to overcoming a design limitation of the Space Shuttle.

  1. SNAP23 Regulates Endothelial Exocytosis of von Willebrand Factor

    PubMed Central

    Zhu, Qiuyu; Yamakuchi, Munekazu; Lowenstein, Charles J.

    2015-01-01

    Endothelial exocytosis regulates vascular thrombosis and inflammation. The trafficking and release of endothelial vesicles is mediated by SNARE (Soluble NSF Attachment protein REceptors) molecules, but the exact identity of endothelial SNAREs has been unclear. Three SNARE molecules form a ternary complex, including isoforms of the syntaxin (STX), vesicle-associated membrane protein (VAMP), and synaptosomal-associated protein (SNAP) families. We now identify SNAP23 as the predominant endothelial SNAP isoform that mediates endothelial exocytosis of von Willebrand Factor (VWF). SNAP23 was localized to the plasma membrane. Knockdown of SNAP23 decreased endothelial exocytosis, suggesting it is important for endothelial exocytosis. SNAP23 interacted with the endothelial exocytic machinery, and formed complexes with other known endothelial SNARE molecules. Taken together, these data suggest that SNAP23 is a key component of the endothelial SNARE machinery that mediates endothelial exocytosis. PMID:26266817

  2. Attachment of Flexible Heparin Chains to Gelatin Scaffolds Improves Endothelial Cell Infiltration

    PubMed Central

    Leijon, Jonas; Carlsson, Fredrik; Brännström, Johan; Sanchez, Javier; Larsson, Rolf; Nilsson, Bo; Rosenquist, Magnus

    2013-01-01

    Long-term survival of implanted cells requires oxygen and nutrients, the need for which is met by vascularization of the implant. The use of scaffolds with surface-attached heparin as anchoring points for angiogenic growth factors has been reported to improve this process. We examined the potential role of surface modification of gelatin scaffolds in promoting endothelial cell infiltration by using a unique macromolecular conjugate of heparin as a coating. Compared to other heparin coatings, this surface modification provides flexible heparin chains, representing a new concept in heparin conjugation. In vitro cell infiltration of scaffolds was assessed using a three-dimensional model in which the novel heparin surface, without growth factors, showed a 2.5-fold increase in the number of infiltrating endothelial cells when compared to control scaffolds. No additional improvement was achieved by adding growth factors (vascular endothelial growth factor and/or fibroblast growth factor-2) to the scaffold. In vivo experiments confirmed these results and also showed that the addition of angiogenic growth factors did not significantly increase the endothelial cell infiltration but increased the number of inflammatory cells in the implanted scaffolds. The endothelial cell-stimulating ability of the heparin surface alone, combined with its growth factor-binding capacity, renders it an interesting candidate surface treatment to create a prevascularized site prepared for implantation of cells and tissues, in particular those sensitive to inflammation but in need of supportive revascularization, such as pancreatic islets of Langerhans. PMID:23327585

  3. Androgen Modulates Functions of Endothelial Progenitor Cells through Activated Egr1 Signaling.

    PubMed

    Ye, Yizhou; Li, Xizhe; Zhang, You; Shen, Zhenya; Yang, Junjie

    2016-01-01

    Researches show that androgens have important effects on migration of endothelial cells and endothelial protection in coronary heart disease. Endothelial progenitor cells (EPCs) as a progenitor cell type that can differentiate into endothelial cells, have a critical role in angiogenesis and endothelial protection. The relationship between androgen and the functions of EPCs has animated much interest and controversy. In this study, we investigated the angiogenic and migratory functions of EPCs after treatment by dihydrotestosterone (DHT) and the molecular mechanisms as well. We found that DHT treatment enhanced the incorporation of EPCs into tubular structures formed by HUVECs and the migratory activity of EPCs in the transwell assay dose dependently. Moreover, microarray analysis was performed to explore how DHT changes the gene expression profiles of EPCs. We found 346 differentially expressed genes in androgen-treated EPCs. Angiogenesis-related genes like Egr-1, Vcan, Efnb2, and Cdk2ap1 were identified to be regulated upon DHT treatment. Furthermore, the enhanced angiogenic and migratory abilities of EPCs after DHT treatment were inhibited by Egr1-siRNA transfection. In conclusion, our findings suggest that DHT markedly enhances the vessel forming ability and migration capacity of EPCs. Egr1 signaling may be a possible pathway in this process. PMID:26697079

  4. Vascular endothelium: functioning in norm, changes in atherosclerosis and current dietary approaches to improve endothelial function.

    PubMed

    Chistiakov, Dimitry A; Revin, Victor V; Sobenin, Igor A; Orekhov, Alexander N; Bobryshev, Yuri V

    2015-01-01

    The endothelium represents not only a simple cellular monolayer that lines the vascular tree in humans and other vertebrates. Depending on the location, the endothelium shows significant morphological and functional heterogeneity through differentiated expression of pro- and anticoagulant factors, presence and frequency of intercellular contacts, variable contractility, cell shape, and volume. Altogether, these properties are crucial for adjustment of the endothelial function and further maintenance of the adequate homeostasis in response in local microenvironmental changes. Endothelial cells (ECs) play a critical role in coordinated regulation of blood flow. This is achieved due to the capacity of ECs to create the active anti-thrombotic surface that supports blood fluidity and transfer of blood cells and biomolecules. However, in certain vascular regions that can occur in inflamed sites or in sites with high hydrodynamic shear stress, ECs could lost their anti-thrombotic properties and switch their normal quiescent phenotype towards the prothrombotic, proadhesion, and proinflammatory state. In such an athero-prone site, the proper endothelial function is impaired that increases risk for formation of the atherosclerotic plaque. The endothelial dysfunction not only precedes atherosclerosis but greatly contributes to atherogenesis in all disease stages. Healthy lifestyle and regular intake of correct antioxidant-rich diet such as fresh fruits, vegetables, olive oil, red wine, and tea have beneficial effects on endothelial function and could therefore reduce the cardiovascular risk. PMID:25723463

  5. DNA-Damage Foci to Detect and Characterize DNA Repair Alterations in Children Treated for Pediatric Malignancies

    PubMed Central

    Kaiser, Mareike; Betten, Dominik; Furtwängler, Rhoikos; Rübe, Christian; Graf, Norbert; Rübe, Claudia E.

    2014-01-01

    Purpose In children diagnosed with cancer, we evaluated the DNA damage foci approach to identify patients with double-strand break (DSB) repair deficiencies, who may overreact to DNA-damaging radio- and chemotherapy. In one patient with Fanconi anemia (FA) suffering relapsing squamous cell carcinomas of the oral cavity we also characterized the repair defect in biopsies of skin, mucosa and tumor. Methods and Materials In children with histologically confirmed tumors or leukemias and healthy control-children DSB repair was investigated by counting γH2AX-, 53BP1- and pATM-foci in blood lymphocytes at defined time points after ex-vivo irradiation. This DSB repair capacity was correlated with treatment-related normal-tissue responses. For the FA patient the defective repair was also characterized in tissue biopsies by analyzing DNA damage response proteins by light and electron microscopy. Results Between tumor-children and healthy control-children we observed significant differences in mean DSB repair capacity, suggesting that childhood cancer is based on genetic alterations affecting DNA repair. Only 1 out of 4 patients with grade-4 normal-tissue toxicities revealed an impaired DSB repair capacity. The defective DNA repair in FA patient was verified in irradiated blood lymphocytes as well as in non-irradiated mucosa and skin biopsies leading to an excessive accumulation of heterochromatin-associated DSBs in rapidly cycling cells. Conclusions Analyzing human tissues we show that DSB repair alterations predispose to cancer formation at younger ages and affect the susceptibility to normal-tissue toxicities. DNA damage foci analysis of blood and tissue samples allows one to detect and characterize DSB repair deficiencies and enables identification of patients at risk for high-grade toxicities. However, not all treatment-associated normal-tissue toxicities can be explained by DSB repair deficiencies. PMID:24637877

  6. The Role of miR-34a in Tritiated Water Toxicity in Human Umbilical Vein Endothelial Cells

    PubMed Central

    Cui, Feng Mei; Liu, Liang; Zheng, Lu Lin; Bao, Guang Liang; Tu, Yu; Sun, Liang; Zhu, Wei; Cao, Jian Ping; Zhou, Ping Kun

    2016-01-01

    In this work, we investigated the toxic effects of tritiated water (HTO) on the cardiovascular system. We examined the role of microRNA-34a (miR-34a) in DNA damage and repair in human umbilical vein endothelial cells (HUVECs) exposed to HTO. Cell proliferation capacity was evaluated by cell counting, and miR-34a expression was detected using quantitative PCR (QT-PCR). The Comet assay and γ-H2AX immunostaining were used to measure DNA double-strand breaks (DSBs). Reverse transcription polymerase chain reaction was used to measure the expression level of c-myc messenger RNA (mRNA). The cells exposed to HTO showed significantly lower proliferation than the control cells over 3 days. The DNA damage in the HTO group was more severe than that in the control group, at each time point examined. The expression of miR-34a mimics caused increased DNA DSBs whereas that of the miR-34a inhibitor caused decreased DNA DSBs. The proliferation viability was the opposite for the miR-34a mimics and inhibitor groups. The expression levels of c-myc mRNA in cells transfected with miR-34a mimics were lower than that in cells transfected with the miR-34a-5p inhibitor, at 0.5 hours and 2 hours after transfection. In summary, miR-34a mediates HTO toxicity in HUVECs by downregulating the expression of c-myc. PMID:27099602

  7. DNA repair in Chromobacterium violaceum.

    PubMed

    Duarte, Fábio Teixeira; Carvalho, Fabíola Marques de; Bezerra e Silva, Uaska; Scortecci, Kátia Castanho; Blaha, Carlos Alfredo Galindo; Agnez-Lima, Lucymara Fassarella; Batistuzzo de Medeiros, Silvia Regina

    2004-03-31

    Chromobacterium violaceum is a Gram-negative beta-proteobacterium that inhabits a variety of ecosystems in tropical and subtropical regions, including the water and banks of the Negro River in the Brazilian Amazon. This bacterium has been the subject of extensive study over the last three decades, due to its biotechnological properties, including the characteristic violacein pigment, which has antimicrobial and anti-tumoral activities. C. violaceum promotes the solubilization of gold in a mercury-free process, and has been used in the synthesis of homopolyesters suitable for the production of biodegradable polymers. The complete genome sequence of this organism has been completed by the Brazilian National Genome Project Consortium. The aim of our group was to study the DNA repair genes in this organism, due to their importance in the maintenance of genomic integrity. We identified DNA repair genes involved in different pathways in C. violaceum through a similarity search against known sequences deposited in databases. The phylogenetic analyses were done using programs of the PHILYP package. This analysis revealed various metabolic pathways, including photoreactivation, base excision repair, nucleotide excision repair, mismatch repair, recombinational repair, and the SOS system. The similarity between the C. violaceum sequences and those of Neisserie miningitidis and Ralstonia solanacearum was greater than that between the C. violaceum and Escherichia coli sequences. The peculiarities found in the C. violaceum genome were the absence of LexA, some horizontal transfer events and a large number of repair genes involved with alkyl and oxidative DNA damage.

  8. N-cadherin coordinates AMP kinase-mediated lung vascular repair.

    PubMed

    Jian, Ming-Yuan; Liu, Yanping; Li, Qian; Wolkowicz, Paul; Alexeyev, Mikhail; Zmijewski, Jaroslaw; Creighton, Judy

    2016-01-01

    Injury to the pulmonary circulation compromises endothelial barrier function and increases lung edema. Resolution of lung damage involves restoring barrier integrity, a process requiring reestablishment of endothelial cell-cell adhesions. However, mechanisms underlying repair in lung endothelium are poorly understood. In pulmonary microvascular endothelium, AMP kinase α1 (AMPKα1) stimulation enhances recovery of the endothelial barrier after LPS-induced vascular damage. AMPKα1 colocalizes to a discrete membrane compartment with the adhesion protein neuronal cadherin (N-cadherin). This study sought to determine N-cadherin's role in the repair process. Short-hairpin RNA against full-length N-cadherin or a C-terminally truncated N-cadherin, designed to disrupt the cadherin's interactions with intracellular proteins, were expressed in lung endothelium. Disruption of N-cadherin's intracellular domain caused translocation of AMPK away from the membrane and attenuated AMPK-mediated restoration of barrier function in LPS-treated endothelium. AMPK activity measurements indicated that lower basal AMPK activity in cells expressing the truncated N-cadherin compared with controls. Moreover, the AMPK stimulator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) failed to increase AMPK activity in cells expressing the modified N-cadherin, indicating uncoupling of a functional association between AMPK and the cadherin. Isolated lung studies confirmed a physiologic role for this pathway in vivo. AMPK activation reversed LPS-induced increase in permeability, whereas N-cadherin inhibition hindered AMPK-mediated repair. Thus N-cadherin coordinates the vascular protective actions of AMPK through a functional link with the kinase. This study provides insight into intrinsic repair mechanisms in the lung and supports AMPK stimulation as a modality for treating vascular disease.

  9. DNA repair in Mycoplasma gallisepticum

    PubMed Central

    2013-01-01

    Background DNA repair is essential for the maintenance of genome stability in all living beings. Genome size as well as the repertoire and abundance of DNA repair components may vary among prokaryotic species. The bacteria of the Mollicutes class feature a small genome size, absence of a cell wall, and a parasitic lifestyle. A small number of genes make Mollicutes a good model for a “minimal cell” concept. Results In this work we studied the DNA repair system of Mycoplasma gallisepticum on genomic, transcriptional, and proteomic levels. We detected 18 out of 22 members of the DNA repair system on a protein level. We found that abundance of the respective mRNAs is less than one per cell. We studied transcriptional response of DNA repair genes of M. gallisepticum at stress conditions including heat, osmotic, peroxide stresses, tetracycline and ciprofloxacin treatment, stationary phase and heat stress in stationary phase. Conclusions Based on comparative genomic study, we determined that the DNA repair system M. gallisepticum includes a sufficient set of proteins to provide a cell with functional nucleotide and base excision repair and mismatch repair. We identified SOS-response in M. gallisepticum on ciprofloxacin, which is a known SOS-inducer, tetracycline and heat stress in the absence of established regulators. Heat stress was found to be the strongest SOS-inducer. We found that upon transition to stationary phase of culture growth transcription of DNA repair genes decreases dramatically. Heat stress does not induce SOS-response in a stationary phase. PMID:24148612

  10. [Endothelial function: role, assessment and limits].

    PubMed

    Puissant, C; Abraham, P; Durand, S; Humeau-Heurtier, A; Faure, S; Rousseau, P; Mahé, G

    2014-02-01

    For several years, detecting and preventing cardiovascular diseases have become a major issue. Different methods have been developed to evaluate endothelial function. Endothelial dysfunction is one of the first steps leading to atherosclerosis. This review presents an insight into endothelial function, the interests of its assessment and methods for studying endothelial function. To date, the vascular endothelium must be considered as a specific organ with its own functions that contribute to the homeostasis of the cardiovascular system. Endothelial dysfunction typically corresponds to a decrease of nitric oxide NO bioavailability. Biological or physico-chemical methods may be used to assess dysfunction. Biological methods allow measuring NO metabolites and pro-inflammatory and vasoconstrictor mediators released by the endothelium. The physico-chemical methods include intra-coronary injections, plethysmography, flow-mediated dilation (FMD), digital plethysmography and optical techniques using laser (laser Doppler single-point, laser Doppler imager, laser speckle contrast imaging) that can be coupled with provocation tests (iontophoresis, microdialysis, post-ischemic hyperemia, local heating). The principle of each technique and its use in clinical practice are discussed. Studying endothelial dysfunction is a particularly promising field because of new drugs being developed. Nevertheless, assessment methodology still needs further development to enable reliable, non-invasive, reproducible, and inexpensive ways to analyze endothelial dysfunction.

  11. Interleukin-1 and tumor necrosis factor alpha inhibit repair of the porcine meniscus in vitro

    PubMed Central

    Hennerbichler, Alfred; Moutos, Franklin T.; Hennerbichler, Diana; Weinberg, J. Brice; Guilak, Farshid

    2011-01-01

    OBJECTIVE Injury or removal of the knee meniscus leads to progressive joint degeneration, and current surgical therapies for meniscal tears seek to maximally preserve meniscal structure and function. However, the factors that influence intrinsic repair of the meniscus are not well understood. The goal of this study was to investigate the capacity of meniscus tissue to repair a simulated defect in vitro and to examine the effect of pro-inflammatory cytokines on this process. METHODS Cylindrical explants were harvested from the outer one-third of medial porcine menisci. To simulate a full-thickness defect, a central core was removed and reinserted immediately into the defect. Explants were cultured for 2, 4, or 6 weeks in serum-containing media in the presence or absence of interleukin-1 (IL-1) or tumor necrosis factor alpha (TNF-alpha), and meniscal repair was investigated using mechanical testing and fluorescence confocal microscopy. RESULTS Meniscal lesions in untreated samples showed a significant capacity for intrinsic repair in vitro, with increasing cell accumulation and repair strength over time in culture. In the presence of IL-1 or TNF-alpha, no repair was observed despite the presence of abundant viable cells. CONCLUSIONS This study demonstrates that the meniscus exhibits an intrinsic repair response in vitro. However, the presence of pro-inflammatory cytokines completely inhibited repair. These findings suggest that increased levels of pro-inflammatory cytokines post-injury or under arthritic conditions may inhibit meniscal repair. Therefore, inhibition of these cytokines may provide a means of accelerating repair of damaged or injured menisci in vivo. PMID:17448702

  12. Myeloid Cells in Cutaneous Wound Repair.

    PubMed

    Cash, Jenna L; Martin, Paul

    2016-06-01

    Cutaneous wound repair is a complex, dynamic process with the goal of rapidly sealing any breach in the skin's protective barrier. Myeloid cells compose a significant proportion of the inflammatory cells recruited to a wound site and play important roles in decontaminating the injured tissue of any invading microorganisms. Subsequently, myeloid cells are able to influence many aspects of the healing response, in part through their capacity to release a large array of signaling molecules that allow them to communicate with and regulate the behavior of other wound cells and in turn, be themselves exquisitely regulated by the wound microenvironment. Macrophages, for example, appear to play important, temporally changing roles in the initiation of scarring and subsequently in matrix remodeling to resolve fibrosis. In this way, myeloid cells seem to play both positive (e.g., pathogen killing and matrix remodeling) and negative (e.g., scarring) roles in wound repair. Further research is of course needed to elucidate the precise temporal and spatial myeloid cell phenotypes and behaviors and ultimately to design effective strategies to optimize the beneficial functions of these cells while minimizing their detrimental contributions to improve wound healing in the clinic. PMID:27337466

  13. Endothelial Heparan Sulfate in Angiogenesis

    PubMed Central

    Fuster, Mark M.; Wang, Lianchun

    2013-01-01

    Heparan sulfate (HS) is a linear polysaccharide composed of 50–200 glucosamine and uronic acid (glucuronic acid or iduronic acid) disaccharide repeats with epimerization and various sulfation modifications. HS is covalently attached to core proteins to form HS-proteoglycans. Most of the functions of HS-proteoglycans are mediated by their HS moieties. The biosynthesis of HS is initiated by chain polymerization and is followed by stepwise modification reactions, including sulfation and epimerization. These modifications generate ligand-binding sites that modulate cell functions and activities of proteinases and/or proteinase inhibitors. HS is abundantly expressed in developing and mature vasculature, and understanding its roles in vascular biology and related human diseases is an area of intense investigation. In this chapter, we summarize the significant recent advances in our understanding of the roles of HS in developmental and pathological angiogenesis with a major focus on studies using transgenic as well as gene knockout/knockdown models in mice and zebrafish. These studies have revealed that HS critically regulates angiogenesis by playing a proangiogenic role, and this regulatory function critically depends on HS fine structure. The latter is responsible for facilitating cell-surface binding of various proangiogenic growth factors that in turn mediate endothelial growth signaling. In cancer, mouse studies have revealed important roles for endothelial cell-surface HS as well as matrix-associated HS, wherein signaling by multiple growth factors as well as matrix storage of growth factors may be regulated by HS. We also discuss important mediators that may fine-tune such regulation, such as heparanase and sulfatases; and models wherein targeting HS (or core protein) biosynthesis may affect tumor growth and vascularization. Finally, the importance of targeting HS in other human diseases wherein angiogenesis may play pathophysiologic (or even therapeutic) roles

  14. Role of Lipotoxicity in Endothelial Dysfunction

    PubMed Central

    Kim, Jeong-a; Montagnani, Monica; Chandrasekran, Sruti; Quon, Michael J.

    2014-01-01

    SUMMARY Lipotoxicity, caused in large part by overnutrition, directly leads to endothelial dysfunction. Excess lipids in both the circulation and at the tissue level contribute to endothelial dysfunction that underlies much of the pathophysiology of both metabolic disease, including obesity and diabetes and their CV complications. Direct lipotoxic effects on other organs as well as secondary insults from endothelial dysfunction synergize to cause substantial morbidity and mortality. Lifestyle interventions, including reduced calorie intake, diet, and exercise as well as a variety of pharmacologic interventions targeting various mechanisms underlying lipotoxicity in vascular endothelium significantly modify metabolic and CV risk. PMID:22999242

  15. Circulating endothelial cells: a new biomarker of endothelial dysfunction in hematological diseases.

    PubMed

    Gendron, Nicolas; Smadja, David M

    2016-08-01

    The endothelium and its integrity are in the center of numerous cardiovascular, pulmonary and tumoral diseases. Several studies identified different circulating cellular sub-populations, which allow a noninvasive exploration of endothelial dysfunction. Furthermore, angiogenesis plays a major role in the biology of benign and malignant hematologic diseases. Among these biomarkers, circulating endothelial cells could be considered as a marker of endothelial injury and/or endothelial activation as well as vascular remodeling, whereas circulating endothelial progenitor cells would be only involved in the vascular regeneration. In the future, the quantification of circulating endothelial cells in many diseases could be a noninvasive biomarker used in diagnosis, prognostic and therapeutic follow-up of lung vasculopathy and/or residual disease of hematological malignancies.

  16. 40 CFR 63.1005 - Leak repair.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... successful repair of the leak. (3) Maximum instrument reading measured by Method 21 of 40 CFR part 60... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Leak repair. 63.1005 Section 63.1005... Standards for Equipment Leaks-Control Level 1 § 63.1005 Leak repair. (a) Leak repair schedule. The owner...

  17. 40 CFR 63.1024 - Leak repair.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reading measured by Method 21 of 40 CFR part 60, appendix A at the time the leak is successfully repaired... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Leak repair. 63.1024 Section 63.1024... Standards for Equipment Leaks-Control Level 2 Standards § 63.1024 Leak repair. (a) Leak repair schedule....

  18. 40 CFR 63.1024 - Leak repair.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reading measured by Method 21 of 40 CFR part 60, appendix A at the time the leak is successfully repaired... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Leak repair. 63.1024 Section 63.1024... Standards for Equipment Leaks-Control Level 2 Standards § 63.1024 Leak repair. (a) Leak repair schedule....

  19. 40 CFR 63.1005 - Leak repair.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... successful repair of the leak. (3) Maximum instrument reading measured by Method 21 of 40 CFR part 60... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Leak repair. 63.1005 Section 63.1005... Standards for Equipment Leaks-Control Level 1 § 63.1005 Leak repair. (a) Leak repair schedule. The owner...

  20. Concomitant Retrograde Coronary Venous Infusion of Basic Fibroblast Growth Factor Enhances Engraftment and Differentiation of Bone Marrow Mesenchymal Stem Cells for Cardiac Repair after Myocardial Infarction

    PubMed Central

    Wang, Xiao; Zhen, Lei; Miao, Huangtai; Sun, Qiwei; Yang, Ya; Que, Bin; Lopes Lao, Edmundo Patricio; Wu, Xingxin; Ren, Hongmei; Shi, Shutian; Lau, Wayne B.; Ma, Xinliang; Ma, Changsheng; Nie, Shaoping

    2015-01-01

    Aim: Basic fibroblast growth factor (bFGF) increases the migration and viability of bone marrow mesenchymal stem cells (MSCs) in vitro. Retrograde coronary venous infusion can provide both increased regional bFGF concentrations and homogeneous cell dissemination. We determined whether retrograde delivery of bFGF enhances the potency of transplanted MSCs for cardiac repair in a canine infarct model. Methods and Results: Under hypoxic conditions, cellular migration was significantly increased in MSCs co-cultured with bFGF compared to vascular endothelial growth factor or insulin-like growth factor, and bFGF promoted MSCs differentiation into a cardiomyocyte phenotype. A canine infarct model was employed by coronary ligation. One week later, animals were subjected to retrograde infusion of combination bFGF (200ng/mL) and MSCs (1×108 cells) (n=5), MSCs (1×108 cells, n=5), bFGF (200ng/mL, n=5), or placebo (phosphate-buffered saline, n=3). Four weeks after infusion, only the bFGF+MSCs therapy exhibited significantly increased left ventricular ejection fraction (LVEF) by echocardiography (p<0.01 vs pre-infusion), and the treatment effect (delta LVEF) was greater in the bFGF+MSCs group compared to saline (7.43±1.51% versus -10.07±2.94%; p<0.001). Morphologic analysis revealed an increased infarct wall thickness in the bFGF+MSCs group compared to all others (p<0.05), accompanied by increased vascular density and reduced apoptosis. Immunofluorescence demonstrated increased cell engraftment and enhanced vascular differentiation in the bFGF+MSCs group compared to MSCs alone (p<0.05). Conclusions: Retrograde coronary venous bFGF infusion augments engraftment and differentiation capacity of transplanted MSCs, recovering cardiac function and preventing adverse remodeling. This novel combined treatment and delivery method is a promising strategy for cardiac repair after ischemic injury. PMID:26155315

  1. Mammalian DNA Repair. Final Report

    SciTech Connect

    2003-01-24

    The Gordon Research Conference (GRC) on Mammalian DNA Repair was held at Harbortown Resort, Ventura Beach, CA. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  2. Nucleotide excision repair in humans.

    PubMed

    Spivak, Graciela

    2015-12-01

    The demonstration of DNA damage excision and repair replication by Setlow, Howard-Flanders, Hanawalt and their colleagues in the early 1960s, constituted the discovery of the ubiquitous pathway of nucleotide excision repair (NER). The serial steps in NER are similar in organisms from unicellular bacteria to complex mammals and plants, and involve recognition of lesions, adducts or structures that disrupt the DNA double helix, removal of a short oligonucleotide containing the offending lesion, synthesis of a repair patch copying the opposite undamaged strand, and ligation, to restore the DNA to its original form. The transcription-coupled repair (TCR) subpathway of NER, discovered nearly two decades later, is dedicated to the removal of lesions from the template DNA strands of actively transcribed genes. In this review I will outline the essential factors and complexes involved in NER in humans, and will comment on additional factors and metabolic processes that affect the efficiency of this important process. PMID:26388429

  3. Nuclear compartmentalization of DNA repair.

    PubMed

    Kalousi, Alkmini; Soutoglou, Evi

    2016-04-01

    The continuous threats on genome integrity by endogenous and exogenous sources have rendered cells competent to overcome these challenges by activating DNA repair pathways. A complex network of proteins and their modifications participate in orchestrated signaling cascades, which are induced in response to DNA damage and may determine the choice of repair pathway. In this review, we summarize recent findings in the field of DNA Double Strand Break repair with regard to the positioning of the break in the highly compartmentalized nucleus. We aim to highlight the importance of chromatin state along with the nuclear position of the DNA lesions on the choice of DNA repair pathway and maintenance of genome integrity. PMID:27266837

  4. Rotator cuff repair - series (image)

    MedlinePlus

    ... shoulder and arm bones. The tendons can be torn from overuse or injury. ... Surgery to repair a torn rotator cuff is usually very successful at relieving pain in the shoulder. The procedure is less predictable at returning strength ...

  5. Precision Instrument and Equipment Repairers.

    ERIC Educational Resources Information Center

    Wyatt, Ian

    2001-01-01

    Explains the job of precision instrument and equipment repairers, who work on cameras, medical equipment, musical instruments, watches and clocks, and industrial measuring devices. Discusses duties, working conditions, employment and earnings, job outlook, and skills and training. (JOW)

  6. How the brain repairs stuttering.

    PubMed

    Kell, Christian A; Neumann, Katrin; von Kriegstein, Katharina; Posenenske, Claudia; von Gudenberg, Alexander W; Euler, Harald; Giraud, Anne-Lise

    2009-10-01

    Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of developmental plasticity. Here we explore what distinguishes this type of recovery from less optimal repair modes, i.e. therapy-induced assisted recovery and attempted compensation in subjects who are still affected. We show that persistent stuttering is associated with mobilization of brain regions contralateral to the structural anomalies for compensation attempt. In contrast, the only neural landmark of optimal repair is activation of the left BA 47/12 in the orbitofrontal cortex, adjacent to a region where a white matter anomaly is observed in persistent stutterers, but normalized in recovered subjects. These findings show that late repair of neurodevelopmental stuttering follows the principles of contralateral and perianomalous reorganization.

  7. Fibroblast-Endothelial Partners for Vascularization Strategies in Tissue Engineering

    PubMed Central

    Costa-Almeida, Raquel; Gomez-Lazaro, Maria; Ramalho, Carla; Soares, Raquel; Guerreiro, Susana G.

    2015-01-01

    Cell-based approaches have emerged as a promising therapy to achieve successful vascularization in tissue engineering. Since fibroblasts activation and migration is required for physiological events relying on angiogenesis, we hypothesize herein that different fibroblasts exhibit distinct capacity to promote capillary-like structures assembly, by mature and progenitor endothelial cells (ECs). Outgrowth endothelial cells (OECs) were isolated from human umbilical cord blood samples and characterized by immunofluorescence and imaging flow cytometry for endothelial markers. Coculture systems were established using either human umbilical vein ECs (HUVECs) or OECs with fibroblasts, being evaluated at 7, 14, and 21 days of culture. Two types of human dermal fibroblasts (HDF) were used, namely neonatal human foreskin fibroblasts-1 (HFF-1) and juvenile HDF. OECs expressed EC markers and formed capillary-like structures. HFF-1 exhibited higher expression of transglutaminase-2, while HDF exhibited a higher expression of α-smooth muscle actin (α-SMA) and podoplanin, which were not observed for HFF-1. Formation of capillary-like structures was only observed in cocultures with HDF and not with HFF-1. No significant differences were found between HDF and OECs or HUVECs cocultures. These findings suggest that HDF is a preferential cell source for promoting vascularization, either using mature or progenitor ECs, probably due to their higher expression of α-SMA and podoplanin, and increased synthesis of extracellular matrix. This work opens new research possibilities regarding the use of specific fibroblast populations cocultured with ECs, as efficient partners for vascular development in regenerative medicine strategies. PMID:25340984

  8. IL-1alpha induces angiogenesis in brain endothelial cells in vitro: implications for brain angiogenesis after acute injury.

    PubMed

    Salmeron, Kathleen; Aihara, Takuma; Redondo-Castro, Elena; Pinteaux, Emmanuel; Bix, Gregory

    2016-02-01

    Inflammation is a major contributor to neuronal injury and is associated with poor outcome after acute brain injury such as stroke. The pro-inflammatory cytokine interleukin (IL)-1 is a critical regulator of cerebrovascular inflammation after ischemic injury, mainly through action of both of its isoforms, IL-1α and IL-1β, at the brain endothelium. In contrast, the differential action of these ligands on endothelial activation and post-stroke angiogenesis is largely unknown. Here, we demonstrate that IL-1α is chronically elevated in the brain after experimental stroke suggesting that it is present during post-stroke angiogenic periods. Furthermore, we demonstrate that IL-1α is a potent mediator of endothelial activation and inducer of angiogenic markers in endothelial cells in vitro. Using brain endothelial cell lines, we found that IL-1α was significantly more potent than IL-1β at inducing endothelial cell activation, as measured by expression of the pro-angiogenic chemokine CXCL-1. IL-1α also induced strong expression of the angiogenic mediator IL-6 in a concentration-dependent manner. Furthermore, IL-1α induced significant proliferation and migration of endothelial cells, and promoted formation of tube-like structures that are established key hallmarks of angiogenesis in vitro. Finally, all of those responses were blocked by the IL-1 receptor antagonist (IL-1RA). In conclusion, our data highlights a potential new role for IL-1 in brain repair mechanisms and identifies IL-1α as a potential new therapy to promote post-stroke angiogenesis. Inflammation is a major contributor to neuronal injury and is associated with poor outcome after neurotrauma. We demonstrate that cytokine IL-1α is chronically elevated in the brain after experimental stroke suggesting that it is present chronically post-stroke. We demonstrate that IL-1α is a potent mediator of endothelial activation and inducer of angiogenic markers in endothelial cells. Our data highlights a new

  9. Endothelial glycocalyx conditions influence nanoparticle uptake for passive targeting.

    PubMed

    Cheng, Ming J; Kumar, Rajiv; Sridhar, Srinivas; Webster, Thomas J; Ebong, Eno E

    2016-01-01

    Cardiovascular diseases are facilitated by endothelial cell (EC) dysfunction and coincide with EC glycocalyx coat shedding. These diseases may be prevented by delivering medications to affected vascular regions using circulating nanoparticle (NP) drug carriers. The objective of the present study was to observe how the delivery of 10 nm polyethylene glycol-coated gold NPs (PEG-AuNP) to ECs is impacted by glycocalyx structure on the EC surface. Rat fat pad endothelial cells were chosen for their robust glycocalyx, verified by fluorescent immunolabeling of adsorbed albumin and integrated heparan sulfate (HS) chains. Confocal fluorescent imaging revealed a ~3 µm thick glycocalyx layer, covering 75% of the ECs and containing abundant HS. This healthy glycocalyx hindered the uptake of PEG-AuNP as expected because glycocalyx pores are typically 7 nm wide. Additional glycocalyx models tested included: a collapsed glycocalyx obtained by culturing cells in reduced protein media, a degraded glycocalyx obtained by applying heparinase III enzyme to specifically cleave HS, and a recovered glycocalyx obtained by supplementing exogenous HS into the media after enzyme degradation. The collapsed glycocalyx waŝ2 µm thick with unchanged EC coverage and sustained HS content. The degraded glycocalyx showed similar changes in EC thickness and coverage but its HS thickness was reduced to 0.7 µm and spanned only 10% of the original EC surface. Both dysfunctional models retained six- to sevenfold more PEG-AuNP compared to the healthy glycocalyx. The collapsed glycocalyx permitted NPs to cross the glycocalyx into intracellular spaces, whereas the degraded glycocalyx trapped the PEG-AuNP within the glycocalyx. The repaired glycocalyx model partially restored HS thickness to 1.2 µm and 44% coverage of the ECs, but it was able to reverse the NP uptake back to baseline levels. In summary, this study showed that the glycocalyx structure is critical for NP uptake by ECs and may serve as a

  10. Endothelial glycocalyx conditions influence nanoparticle uptake for passive targeting

    PubMed Central

    Cheng, Ming J; Kumar, Rajiv; Sridhar, Srinivas; Webster, Thomas J; Ebong, Eno E

    2016-01-01

    Cardiovascular diseases are facilitated by endothelial cell (EC) dysfunction and coincide with EC glycocalyx coat shedding. These diseases may be prevented by delivering medications to affected vascular regions using circulating nanoparticle (NP) drug carriers. The objective of the present study was to observe how the delivery of 10 nm polyethylene glycol-coated gold NPs (PEG-AuNP) to ECs is impacted by glycocalyx structure on the EC surface. Rat fat pad endothelial cells were chosen for their robust glycocalyx, verified by fluorescent immunolabeling of adsorbed albumin and integrated heparan sulfate (HS) chains. Confocal fluorescent imaging revealed a ~3 µm thick glycocalyx layer, covering 75% of the ECs and containing abundant HS. This healthy glycocalyx hindered the uptake of PEG-AuNP as expected because glycocalyx pores are typically 7 nm wide. Additional glycocalyx models tested included: a collapsed glycocalyx obtained by culturing cells in reduced protein media, a degraded glycocalyx obtained by applying heparinase III enzyme to specifically cleave HS, and a recovered glycocalyx obtained by supplementing exogenous HS into the media after enzyme degradation. The collapsed glycocalyx waŝ2 µm thick with unchanged EC coverage and sustained HS content. The degraded glycocalyx showed similar changes in EC thickness and coverage but its HS thickness was reduced to 0.7 µm and spanned only 10% of the original EC surface. Both dysfunctional models retained six- to sevenfold more PEG-AuNP compared to the healthy glycocalyx. The collapsed glycocalyx permitted NPs to cross the glycocalyx into intracellular spaces, whereas the degraded glycocalyx trapped the PEG-AuNP within the glycocalyx. The repaired glycocalyx model partially restored HS thickness to 1.2 µm and 44% coverage of the ECs, but it was able to reverse the NP uptake back to baseline levels. In summary, this study showed that the glycocalyx structure is critical for NP uptake by ECs and may serve as a

  11. Upregulation of the low density lipoprotein receptor at the blood-brain barrier: intercommunications between brain capillary endothelial cells and astrocytes

    PubMed Central

    1994-01-01

    In contrast to the endothelial cells in large vessels where LDL receptors are downregulated, brain capillary endothelial cells in vivo express an LDL receptor. Using a cell culture model of the blood-brain barrier consisting of a coculture of brain capillary endothelial cells and astrocytes, we observed that the capacity of endothelial cells to bind LDL is enhanced threefold when cocultured with astrocytes. We next investigated the ability of astrocytes to modulate endothelial cell LDL receptor expression. We have shown that the lipid requirement of astrocytes increases the expression of endothelial cell LDL receptors. Experiments with dialysis membranes of different pore size showed that this effect is mediated by a soluble factor(s) with relative molecular mass somewhere between 3,500 and 14,000. Substituting astrocytes with smooth muscle cells or brain endothelium with endothelium from the aorta or the adrenal cortex did not enhance the luminal LDL receptor expression on endothelial cells, demonstrating the specificity of the interactions. This factor(s) is exclusively secreted by astrocytes cocultured with brain capillary endothelial cells, but it also upregulates the LDL receptor on other cell types. This study confirms the notion that the final fine tuning of cell differentiation is under local control. PMID:8034745

  12. DNA Repair in Human Pluripotent Stem Cells Is Distinct from That in Non-Pluripotent Human Cells

    PubMed Central

    Luo, Li Z.; Park, Sang-Won; Bates, Steven E.; Zeng, Xianmin; Iverson, Linda E.; O'Connor, Timothy R.

    2012-01-01

    The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use. PMID:22412831

  13. Aircraft Metal Skin Repair and Honeycomb Structure Repair; Sheet Metal Work 3: 9857.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course helps students determine types of repairs, compute repair sizes, and complete the repair through surface protection. Course content includes goals, specific objectives, protection of metals, repairs to metal skin, and honeycomb structure repair. A bibliography and post-test are appended. A prerequisite for this course is mastery of the…

  14. Asiaticoside Inhibits TNF-α-Induced Endothelial Hyperpermeability of Human Aortic Endothelial Cells.

    PubMed

    Fong, Lai Yen; Ng, Chin Theng; Zakaria, Zainul Amiruddin; Baharuldin, Mohamad Taufik Hidayat; Arifah, Abdul Kadir; Hakim, Muhammad Nazrul; Zuraini, Ahmad

    2015-10-01

    The increase in endothelial permeability often promotes edema formation in various pathological conditions. Tumor necrosis factor-alpha (TNF-α), a pro-atherogenic cytokine, impairs endothelial barrier function and causes endothelial dysfunction in early stage of atherosclerosis. Asiaticoside, one of the triterpenoids derived from Centella asiatica, is known to possess antiinflammatory activity. In order to examine the role of asiaticoside in preserving the endothelial barrier, we assessed its effects on endothelial hyperpermeability and disruption of actin filaments evoked by TNF-α in human aortic endothelial cells (HAEC). TNF-α caused an increase in endothelial permeability to fluorescein isothiocyanate (FITC)-dextran. Asiaticoside pretreatment significantly suppressed TNF-α-induced increased permeability. Asiaticoside also prevented TNF-α-induced actin redistribution by suppressing stress fiber formation. However, the increased F to G actin ratio stimulated by TNF-α was not changed by asiaticoside. Cytochalasin D, an actin depolymerizing agent, was used to correlate the anti-hyperpermeability effect of asiaticoside with actin cytoskeleton. Surprisingly, asiaticoside failed to prevent cytochalasin D-induced increased permeability. These results suggest that asiaticoside protects against the disruption of endothelial barrier and actin rearrangement triggered by TNF-α without a significant change in total actin pool. However, asiaticoside seems to work by other mechanisms to maintain the integrity of endothelial barrier rather than stabilizing the F-actin organization.

  15. Repair Integrity and Clinical Outcomes Following Arthroscopic Rotator Cuff Repair

    PubMed Central

    Williams, Ariel A.; Mark, P.; DiVenere, Jessica Megan; Klinge, Stephen Austin; Arciero, Robert A.; Mazzocca, Augustus D.

    2016-01-01

    Objectives: To prospectively evaluate the effect of early versus delayed motion on repair integrity on 6-month postoperative magnetic resonance imaging (MRI) scans following rotator cuff repair, and to correlate repair integrity with clinical and functional outcomes. We hypothesized that repair integrity would differ between the early and delayed groups and that patients with repair failures would have worse clinical and functional outcomes. Methods: This was a prospective, randomized, single blinded clinical trial comparing an early motion (post-op day 2-3) to a delayed motion (post-op day 28) rehabilitation protocol following arthroscopic repair of isolated supraspinatus tears. All patients underwent MRI at 6 months post-operatively as part of the study protocol. A blinded board-certified and fellowship-trained orthopaedic surgeon (not part of the surgical team) reviewed operative photos and video to confirm the presence of a full thickness supraspinatus tear and to ensure an adequate and consistent repair. The same surgeon along with a blinded sports medicine fellowship-trained musculoskeletal radiologist independently reviewed all MRIs to determine whether the repair was intact at 6 months. Outcome measures were collected by independent evaluators who were also blinded to group assignment. These included the Western Ontario Rotator Cuff (WORC) index, Single Assessment Numeric Evaluation (SANE) ratings, pain scores, sling use, and physical exam data. Enrolled patients were followed at 6 weeks, 6 months, and 1 year. Results: From October 2008 to April 2012, 73 patients met all inclusion criteria and were willing to participate. 36 patients were randomized to delayed motion and 37 were randomized to early motion. The final study group at 6 months consisted of 58 study participants. Postoperative MRIs were obtained on all of these patients at 6 months regardless of whether or not they were progressing as expected. These MRIs demonstrated an overall failure rate of

  16. Soluble endoglin, hypercholesterolemia and endothelial dysfunction.

    PubMed

    Rathouska, Jana; Jezkova, Katerina; Nemeckova, Ivana; Nachtigal, Petr

    2015-12-01

    A soluble form of endoglin (sEng) is known to be an extracellular domain of the full-length membrane endoglin, which is elevated during various pathological conditions related to vascular endothelium. In the current review, we tried to summarize a possible role of soluble endoglin in cardiovascular pathologies, focusing on its relation to endothelial dysfunction and cholesterol levels. We discussed sEng as a proposed biomarker of cardiovascular disease progression, cardiovascular disease treatment and endothelial dysfunction. We also addressed a potential interaction of sEng with TGF-β/eNOS or BMP-9 signaling. We suggest soluble endoglin levels to be monitored, because they reflect the progression/treatment efficacy of cardiovascular diseases related to endothelial dysfunction and hypercholesterolemia. A possible role of soluble endoglin as an inducer of endothelial dysfunction however remains to be elucidated. PMID:26520890

  17. [Descemet's stripping automated endothelial keratoplasty (DSAEK)].

    PubMed

    Cursiefen, C; Kruse, F E

    2009-10-01

    Penetrating keratoplasty has been the gold standard for the surgical treatment of corneal endothelial pathologies, but tremendous progress has been made in recent years in improving the technology of posterior lamellar keratoplasty techniques such as Descemet's stripping automated endothelial keratoplasty (DSAEK). This progress is shown by a literature review using PubMed sources and our own clinical and experimental data. Posterior lamellar keratoplasty using a microkeratome is a reliable surgical technique for Fuchs' endothelial dystrophy and pseudophakic bullous keratopathy. Visual rehabilitation is faster with lamellar compared with penetrating keratoplasty, but final visual acuity seems to be a bit reduced. Posterior lamellar keratoplasty techniques such as DSAEK may replace penetrating keratoplasty as the gold standard for treating a large proportion of corneal endothelial pathologies. PMID:19798505

  18. Genetics Home Reference: Fuchs endothelial dystrophy

    MedlinePlus

    ... a protein that is part of type VIII collagen. Type VIII collagen is largely found within the cornea, surrounding the endothelial cells. Specifically, type VIII collagen is a major component of a tissue at ...

  19. Endothelial glucocorticoid receptor suppresses atherogenesis- Brief Report

    PubMed Central

    Zhang, Xinbo; Rotllan, Noemi; Feng, Yan; Zhou, Han; Fernández-Hernando, Carlos; Yu, Jun; Sessa, William C.

    2015-01-01

    Objective The purpose of this study was to determine the role of the endothelial glucocorticoid receptor in the pathogenesis of atherosclerosis. Approach and Results Control mice and mice lacking the endothelial glucocorticoid receptor were bred onto an Apoe knockout background and subjected to high-fat diet feeding for 12 weeks. Assessment of body weight and total cholesterol and triglycerides before and after the diet revealed no differences between the two groups of mice. However, mice lacking the endothelial glucocorticoid receptor developed more severe atherosclerotic lesions in the aorta, brachiocephalic artery and aortic sinus as well as a heightened inflammatory milieu as evidence by increased macrophage recruitment in the lesions. Conclusions These data suggest the endothelial glucocorticoid receptor is important for tonic inhibition of inflammation and limitation of atherosclerosis progression in this model. PMID:25810297

  20. Endothelial progenitor cells in cardiovascular diseases.

    PubMed

    Lee, Poay Sian Sabrina; Poh, Kian Keong

    2014-07-26

    Endothelial dysfunction has been associated with the development of atherosclerosis and cardiovascular diseases. Adult endothelial progenitor cells (EPCs) are derived from hematopoietic stem cells and are capable of forming new blood vessels through a process of vasculogenesis. There are studies which report correlations between circulating EPCs and cardiovascular risk factors. There are also studies on how pharmacotherapies may influence levels of circulating EPCs. In this review, we discuss the potential role of endothelial progenitor cells as both diagnostic and prognostic biomarkers. In addition, we look at the interaction between cardiovascular pharmacotherapies and endothelial progenitor cells. We also discuss how EPCs can be used directly and indirectly as a therapeutic agent. Finally, we evaluate the challenges facing EPC research and how these may be overcome.

  1. A novel perspective for burn-induced myopathy: Membrane repair defect

    PubMed Central

    Wang, Chao; Wang, Hongyu; Wu, Dan; Hu, Jianhong; Wu, Wei; Zhang, Yong; Peng, Xi

    2016-01-01

    Myopathy is a common complication of severe burn patients. One potential cause of this myopathy could be failure of the plasma membrane to undergo repair following injuries generated from toxin or exercise. The aim of this study is to assess systemic effect on muscle membrane repair deficiency in burn injury. Skeletal muscle fibers isolated from burn-injured mice were damaged with a UV laser and dye influx imaged confocally to evaluate membrane repair capacity. Membrane repair failure was also tested in burn-injured mice subjected to myotoxin or treadmill exercise. We further used C2C12 myotubules and animal models to investigate the role of MG53 in development of burn-induced membrane repair defect. We demonstrated that skeletal muscle myofibers in burn-injured mice showed significantly more dye uptake after laser damage than controls, indicating a membrane repair deficiency. Myotoxin or treadmill exercise also resulted in a higher-grade repair defect in burn-injured mice. Furthermore, we observed that burn injury induced a significant decrease in MG53 levels and its dimerization in skeletal muscles. Our findings highlight a new mechanism that implicates membrane repair failure as an underlying cause of burn-induced myopathy. And, the disorders in MG53 expression and MG53 dimerization are involved in this cellular pathology. PMID:27545095

  2. Approach to In Situ Component Level Electronics Assembly Repair (CLEAR) for Constellation

    NASA Technical Reports Server (NTRS)

    Struk, Peter M.; Oeftering, Richard C.

    2010-01-01

    Maintenance resupply is a significant issue for long duration space missions. Currently, the International Space Station (ISS) approaches maintenance primarily around replaceable modules called Orbital Replacement Units (ORU). While swapping out ORUs has served the ISS well keeping crew time for maintenance to a minimum, this approach assumes a substantial logistics capacity to provide replacement ORUs and return ORUs to Earth for repair. The ORUs used for ISS require relatively large blocks of replacement hardware even though the actual failed component may be several orders of magnitude smaller. The Component Level Electronics Assembly Repair (CLEAR) task was created to explore electronics repair down to the component level for future space missions. From 2006 to 2009, CLEAR was an activity under the Supportability project of the Exploration Technology Development Program. This paper describes the activities of CLEAR including making a case for component-level electronics repair, examination of current terrestrial repair hardware, and potential repair needs. Based on those needs, the CLEAR team proposes an architecture for an in-situ repair capability aboard a spacecraft or habitat. Additionally, this paper discusses recent progress toward developing in-space repair capabilities--including two spaceflight experiments-- and presents technology concepts which could help enable or benefit the same.

  3. Repairing of N-mustard derivative BO-1055 induced DNA damage requires NER, HR, and MGMT-dependent DNA repair mechanisms.

    PubMed

    Kuo, Ching-Ying; Chou, Wen-Cheng; Wu, Chin-Chung; Wong, Teng-Song; Kakadiya, Rajesh; Lee, Te-Chang; Su, Tsann-Long; Wang, Hui-Chun

    2015-09-22

    Alkylating agents are frequently used as first-line chemotherapeutics for various newly diagnosed cancers. Disruption of genome integrity by such agents can lead to cell lethality if DNA lesions are not removed. Several DNA repair mechanisms participate in the recovery of mono- or bi-functional DNA alkylation. Thus, DNA repair capacity is correlated with the therapeutic response. Here, we assessed the function of novel water-soluble N-mustard BO-1055 (ureidomustin) in DNA damage response and repair mechanisms. As expected, BO-1055 induces ATM and ATR-mediated DNA damage response cascades, including downstream Chk1/Chk2 phosphorylation, S/G2 cell-cycle arrest, and cell death. Further investigation revealed that cell survival sensitivity to BO-1055 is comparable to that of mitomycin C. Both compounds require nucleotide excision repair and homologous recombination, but not non-homologous end-joining, to repair conventional cross-linking DNA damage. Interestingly and unlike mitomycin C and melphalan, MGMT activity was also observed in BO-1055 damage repair systems, which reflects the occurrence of O-alkyl DNA lesions. Combined treatment with ATM/ATR kinase inhibitors significantly increases BO-1055 sensitivity. Our study pinpoints that BO-1055 can be used for treating tumors that with deficient NER, HR, and MGMT DNA repair genes, or for synergistic therapy in tumors that DNA damage response have been suppressed. PMID:26208482

  4. Repairing of N-mustard derivative BO-1055 induced DNA damage requires NER, HR, and MGMT-dependent DNA repair mechanisms

    PubMed Central

    Wu, Chin-Chung; Wong, Teng-Song; Kakadiya, Rajesh; Lee, Te-Chang; Su, Tsann-Long; Wang, Hui-Chun

    2015-01-01

    Alkylating agents are frequently used as first-line chemotherapeutics for various newly diagnosed cancers. Disruption of genome integrity by such agents can lead to cell lethality if DNA lesions are not removed. Several DNA repair mechanisms participate in the recovery of mono- or bi-functional DNA alkylation. Thus, DNA repair capacity is correlated with the therapeutic response. Here, we assessed the function of novel water-soluble N-mustard BO-1055 (ureidomustin) in DNA damage response and repair mechanisms. As expected, BO-1055 induces ATM and ATR-mediated DNA damage response cascades, including downstream Chk1/Chk2 phosphorylation, S/G2 cell-cycle arrest, and cell death. Further investigation revealed that cell survival sensitivity to BO-1055 is comparable to that of mitomycin C. Both compounds require nucleotide excision repair and homologous recombination, but not non-homologous end-joining, to repair conventional cross-linking DNA damage. Interestingly and unlike mitomycin C and melphalan, MGMT activity was also observed in BO-1055 damage repair systems, which reflects the occurrence of O-alkyl DNA lesions. Combined treatment with ATM/ATR kinase inhibitors significantly increases BO-1055 sensitivity. Our study pinpoints that BO-1055 can be used for treating tumors that with deficient NER, HR, and MGMT DNA repair genes, or for synergistic therapy in tumors that DNA damage response have been suppressed. PMID:26208482

  5. Production, Purification, and Characterization of ¹⁵N-Labeled DNA Repair Proteins as Internal Standards for Mass Spectrometric Measurements.

    PubMed

    Reddy, Prasad T; Jaruga, Pawel; Nelson, Bryant C; Lowenthal, Mark S; Jemth, Ann-Sofie; Loseva, Olga; Coskun, Erdem; Helleday, Thomas; Dizdaroglu, Miral

    2016-01-01

    Oxidatively induced DNA damage is caused in living organisms by a variety of damaging agents, resulting in the formation of a multiplicity of lesions, which are mutagenic and cytotoxic. Unless repaired by DNA repair mechanisms before DNA replication, DNA lesions can lead to genomic instability, which is one of the hallmarks of cancer. Oxidatively induced DNA damage is mainly repaired by base excision repair pathway with the involvement of a plethora of proteins. Cancer tissues develop greater DNA repair capacity than normal tissues by overexpressing DNA repair proteins. Increased DNA repair in tumors that removes DNA lesions generated by therapeutic agents before they became toxic is a major mechanism in the development of therapy resistance. Evidence suggests that DNA repair capacity may be a predictive biomarker of patient response. Thus, knowledge of DNA-protein expressions in disease-free and cancerous tissues may help predict and guide development of treatments and yield the best therapeutic response. Our laboratory has developed methodologies that use mass spectrometry with isotope dilution for the measurement of expression of DNA repair proteins in human tissues and cultured cells. For this purpose, full-length (15)N-labeled analogs of a number of human DNA repair proteins have been produced and purified to be used as internal standards for positive identification and accurate quantification. This chapter describes in detail the protocols of this work. The use of (15)N-labeled proteins as internal standards for the measurement of several DNA repair proteins in vivo is also presented.

  6. Thermal Pretreatment Improves Viability of Cryopreserved Human Endothelial Cells.

    PubMed

    Hofmann, Nicola; Sun, Huan; Chatterjee, Anamika; Saha, Debapriya; Glasmacher, Birgit

    2015-10-01

    A high survival rate of cryopreserved cells requires optimal cooling and thawing rates in the presence of a cryoprotective agent (CPA) or a combination of CPAs in adequate concentrations. One of the most widely used CPAs, dimethyl sulfoxide (Me2SO), however is toxic at high concentrations and has detrimental effects on cellular functions. Additional processing steps are necessary to remove the CPA after thawing, which make the process expensive and time consuming. Therefore it is of great interest to develop new cryoprotective strategies to replace the currently used CPAs or to reduce their concentration. The aim of this study was to investigate if thermal activation of human pulmonary microvascular endothelial cells (HPMEC ST-1.6R), prior to cryopreservation, could improve their post-thaw viability since the resulting heat shock protein expression acts as an intrinsic cellular protection mechanism. The results of this study suggest that both heat and cold shock pretreatments improve cryopreservation outcome of the HPMEC ST-1.6R cells. By re-cultivating cells after heat shock treatment before cryopreservation, a significant increase in cellular membrane integrity and adherence capacity could be achieved. However a combination of thermal activation and cryopreservation with alternative CPAs such as ectoine and L-proline could not further enhance the cell viability. The results of this study showed that pretreatment of endothelial cells with thermal activation could be used to reduce the Me2SO concentration required in order to preserve cell viability after cryopreservation. PMID:26419006

  7. Thermal Pretreatment Improves Viability of Cryopreserved Human Endothelial Cells.

    PubMed

    Hofmann, Nicola; Sun, Huan; Chatterjee, Anamika; Saha, Debapriya; Glasmacher, Birgit

    2015-10-01

    A high survival rate of cryopreserved cells requires optimal cooling and thawing rates in the presence of a cryoprotective agent (CPA) or a combination of CPAs in adequate concentrations. One of the most widely used CPAs, dimethyl sulfoxide (Me2SO), however is toxic at high concentrations and has detrimental effects on cellular functions. Additional processing steps are necessary to remove the CPA after thawing, which make the process expensive and time consuming. Therefore it is of great interest to develop new cryoprotective strategies to replace the currently used CPAs or to reduce their concentration. The aim of this study was to investigate if thermal activation of human pulmonary microvascular endothelial cells (HPMEC ST-1.6R), prior to cryopreservation, could improve their post-thaw viability since the resulting heat shock protein expression acts as an intrinsic cellular protection mechanism. The results of this study suggest that both heat and cold shock pretreatments improve cryopreservation outcome of the HPMEC ST-1.6R cells. By re-cultivating cells after heat shock treatment before cryopreservation, a significant increase in cellular membrane integrity and adherence capacity could be achieved. However a combination of thermal activation and cryopreservation with alternative CPAs such as ectoine and L-proline could not further enhance the cell viability. The results of this study showed that pretreatment of endothelial cells with thermal activation could be used to reduce the Me2SO concentration required in order to preserve cell viability after cryopreservation.

  8. Role of biomechanics on intervertebral disc degeneration and regenerative therapies: What needs repairing in the disc and what are promising biomaterials for its repair?

    PubMed Central

    Iatridis, James C.; Nicoll, Steven B.; Michalek, Arthur J.; Walter, Benjamin A.; Gupta, Michelle S.

    2013-01-01

    Background Context Degeneration and injuries of the intervertebral disc result in large alterations in biomechanical behaviors. Repair strategies using biomaterials can be optimized based on biomechanical and biological requirements. Purpose To review current literature on 1) effects of degeneration, simulated degeneration, and injury on biomechanics of the intervertebral disc with special attention paid to needle puncture injuries which are a pathway for diagnostics and regenerative therapies; and 2) promising biomaterials for disc repair with a focus on how those biomaterials may promote biomechanical repair. Study Design/Setting A narrative review to evaluate the role of biomechanics on disc degeneration and regenerative therapies with a focus on what biomechanical properties need to be repaired and how to evaluate and accomplish such repairs using biomaterials. Model systems for screening of such repair strategies are also briefly described. Methods Papers were selected from two main Pubmed searches using keywords: intervertebral AND biomechanics (1823 articles) and intervertebral AND biomaterials (361 articles). Additional keywords (injury, needle puncture, nucleus pressurization, biomaterials, hydrogel, sealant, tissue engineering) were used to narrow articles to the topics most relevant to this review. Results Degeneration and acute disc injuries have the capacity to influence nucleus pulposus pressurization and annulus fibrosus integrity, which are necessary for effective disc function, and therefore, require repair. Needle injection injuries are of particular clinical relevance with potential to influence disc biomechanics, cellularity, and metabolism, yet these effects are localized or small, and more research is required to evaluate and reduce potential clinical morbidity using such techniques. NP replacement strategies, such as hydrogels, are required to restore NP pressurization or lost volume. AF repair strategies, including crosslinked hydrogels

  9. Heat Capacity Analysis Report

    SciTech Connect

    A. Findikakis

    2004-11-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  10. Caspase-1 mediates hyperlipidemia-weakened progenitor cell vessel repair

    PubMed Central

    Li, Ya-Feng; Huang, Xiao; Li, Xinyuan; Gong, Ren; Yin, Ying; Nelson, Jun; Gao, Erhe; Zhang, Hongyu; Hoffman, Nicholas E.; Houser, Steven R.; Madesh, Muniswamy; Tilley, Douglas G.; Choi, Eric T.; Jiang, Xiaohua; Huang, Cong-Xin; Wang, Hong; Yang, Xiao-Feng

    2015-01-01

    Caspase-1 activation senses metabolic danger-associated molecular patterns (DAMPs) and mediates the initiation of inflammation in endothelial cells. Here, we examined whether the caspase-1 pathway is responsible for sensing hyperlipidemia as a DAMP in bone marrow (BM)-derived Stem cell antigen-1 positive (Sca-1+) stem/progenitor cells and weakening their angiogenic ability. Using biochemical methods, gene knockout, cell therapy and myocardial infarction (MI) models, we had the following findings: 1) Hyperlipidemia induces caspase-1 activity in mouse Sca-1+ progenitor cells in vivo; 2) Caspase-1 contributes to hyperlipidemia-induced modulation of vascular cell death-related gene expression in vivo; 3) Injection of Sca-1+ progenitor cells from caspase-1−/− mice improves endothelial capillary density in heart and decreases cardiomyocyte death in a mouse model of MI; and 4) Caspase-1−/− Sca-1+ progenitor cell therapy improves mouse cardiac function after MI. Our results provide insight on how hyperlipidemia activates caspase-1 in Sca-1+ progenitor cells, which subsequently weakens Sca-1+ progenitor cell repair of vasculature injury. These results demonstrate the therapeutic potential of caspase-1 inhibition in improving progenitor cell therapy for MI. PMID:26709768

  11. Inflammatory and repair serum biomarker pattern. Association to clinical outcomes in COPD

    PubMed Central

    2012-01-01

    Background The relationship between serum biomarkers and clinical expressions of COPD is limited. We planned to further describe this association using markers of inflammation and injury and repair. Methods We studied lung function, comorbidities, exercise tolerance, BODE index, and quality of life in 253 COPD patients and recorded mortality over three years. Serum levels of Interleukins 6,8 and16, tumor necrosis factor alpha (TNF α) [inflammatory panel], vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) [injury and repair panel] and pulmonary and activation-regulated chemokine (PARC/CCL-18) and monocyte chemotactic protein 1 (MCP-1/CCL2) [chemoattractant panel] were measured. We related the pattern of the biomarker levels to minimal clinically important differences (MCID) using a novel visualization method [ObServed Clinical Association Results (OSCAR) plot]. Results Levels of the inflammatory markers IL-6, TNF α were higher and those of injury and repair lower (p < 0.01) with more advanced disease (GOLD 1 vs. 4). Using the OSCAR plot, we found that patients in the highest quartile of inflammatory and lowest quartile of injury and repair biomarkers level were more clinically compromised and had higher mortality (p < 0.05). Conclusions In COPD, serum biomarkers of inflammation and repair are distinctly associated with important clinical parameters and survival. PMID:22906131

  12. Nonequilibrium heat capacity.

    PubMed

    Mandal, Dibyendu

    2013-12-01

    Development of steady state thermodynamics and statistical mechanics depends crucially on our ability to extend the notions of equilibrium thermodynamics to nonequilibrium steady states (NESS). The present paper considers the extension of heat capacity. A modified definition is proposed which continues to maintain the same relation to steady state Shannon entropy as in equilibrium, thus providing a thermodynamically consistent treatment of NESS heat capacity.

  13. Liquid heat capacity lasers

    DOEpatents

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  14. Problems of Excess Capacity

    NASA Technical Reports Server (NTRS)

    Douglas, G.

    1972-01-01

    The problems of excess capacity in the airline industry are discussed with focus on the following topics: load factors; fair rate of return on investment; service-quality rivalry among airlines; pricing (fare) policies; aircraft production; and the impacts of excess capacity on operating costs. Also included is a discussion of the interrelationships among these topics.

  15. Polymorphism of the Flap Endonuclease 1 Gene in Keratoconus and Fuchs Endothelial Corneal Dystrophy

    PubMed Central

    Wojcik, Katarzyna A.; Synowiec, Ewelina; Polakowski, Piotr; Głowacki, Sylwester; Izdebska, Justyna; Lloyd, Sophie; Galea, Dieter; Blasiak, Janusz; Szaflik, Jerzy; Szaflik, Jacek P.

    2014-01-01

    Oxidative stress is implicated in the pathogenesis of many diseases, including serious ocular diseases, keratoconus (KC) and Fuchs endothelial corneal dystrophy (FECD). Flap endonuclease 1 (FEN1) plays an important role in the repair of oxidative DNA damage in the base excision repair pathway. We determined the association between two single nucleotide polymorphisms (SNPs), c.–441G>A (rs174538) and g.61564299G>T (rs4246215), in the FEN1 gene and the occurrence of KC and FECD. This study involved 279 patients with KC, 225 patients with FECD and 322 control individuals. Polymerase chain reaction (PCR) and length polymorphism restriction fragment analysis (RFLP) were applied. The T/T genotype of the g.61564299G>T polymorphism was associated with an increased occurrence of KC and FECD. There was no association between the c.–441G>A polymorphism and either disease. However, the GG haplotype of both polymorphisms was observed more frequently and the GT haplotype less frequently in the KC group than the control. The AG haplotype was associated with increased FECD occurrence. Our findings suggest that the g.61564299G>T and c.–441G>A polymorphisms in the FEN1 gene may modulate the risk of keratoconus and Fuchs endothelial corneal dystrophy. PMID:25153632

  16. Specific role of impaired glucose metabolism and diabetes mellitus in endothelial progenitor cell characteristics and function.

    PubMed

    Yiu, Kai-Hang; Tse, Hung-Fat

    2014-06-01

    The disease burden of diabetes mellitus (DM) and its associated cardiovascular complications represent a growing and major global health problem. Recent studies suggest that circulating exogenous endothelial progenitor cells (EPCs) play an important role in endothelial repair and neovascularization at sites of injury or ischemia. Both experimental and clinical studies have demonstrated that hyperglycemia related to DM can induce alterations to EPCs. The reduction and dysfunction of EPCs related to DM correlate with the occurrence and severity of microvascular and macrovascular complications, suggesting a close mechanistic link between EPC dysfunction and impaired vascular function/repair in DM. These alterations to EPCs, likely mediated by multiple pathophysiological mechanisms, including inflammation, oxidative stress, and alterations in Akt and the nitric oxide pathway, affect EPCs at multiple stages: differentiation and mobilization in the bone marrow, trafficking and survival in the circulation, and homing and neovascularization. Several different therapeutic approaches have consequently been proposed to reverse the reduction and dysfunction of EPCs in DM and may represent a novel therapeutic approach to prevent and treat DM-related cardiovascular complications.

  17. Photosystem II repair in marine diatoms with contrasting photophysiologies.

    PubMed

    Lavaud, Johann; Six, Christophe; Campbell, Douglas A

    2016-02-01

    Skeletonema costatum and Phaeodactylum tricornutum are model marine diatoms with differing strategies for non-photochemical dissipation of excess excitation energy within photosystem II (PSII). We showed that S. costatum, with connectivity across the pigment bed serving PSII, and limited capacity for induction of sustained non-photochemical quenching (NPQ), maintained a large ratio of [PSII(Total)]/[PSII(Active)] to buffer against fluctuations in light intensity. In contrast, P. tricornutum, with a larger capacity to induce sustained NPQ, could maintain a lower [PSII(Total)]/[PSII(Active)]. Induction of NPQ was correlated with an active PSII repair cycle in both species, and inhibition of chloroplastic protein synthesis with lincomycin leads to run away over-excitation of remaining PSII(Active), particularly in S. costatum. We discuss these distinctions in relation to the differing capacities, induction and relaxation rates for NPQ, and as strain adaptations to the differential light regimes of their originating habitats. The present work further confirms the important role for the light-dependent fast regulation of photochemistry by NPQ interacting with PSII repair cycle capacity in the ecophysiology of both pennate and centric diatoms. PMID:26156125

  18. Nanoparticle accumulation and transcytosis in brain endothelial cell layers

    NASA Astrophysics Data System (ADS)

    Ye, Dong; Raghnaill, Michelle Nic; Bramini, Mattia; Mahon, Eugene; Åberg, Christoffer; Salvati, Anna; Dawson, Kenneth A.

    2013-10-01

    The blood-brain barrier (BBB) is a selective barrier, which controls and limits access to the central nervous system (CNS). The selectivity of the BBB relies on specialized characteristics of the endothelial cells that line the microvasculature, including the expression of intercellular tight junctions, which limit paracellular permeability. Several reports suggest that nanoparticles have a unique capacity to cross the BBB. However, direct evidence of nanoparticle transcytosis is difficult to obtain, and we found that typical transport studies present several limitations when applied to nanoparticles. In order to investigate the capacity of nanoparticles to access and transport across the BBB, several different nanomaterials, including silica, titania and albumin- or transferrin-conjugated gold nanoparticles of different sizes, were exposed to a human in vitro BBB model of endothelial hCMEC/D3 cells. Extensive transmission electron microscopy imaging was applied in order to describe nanoparticle endocytosis and typical intracellular localisation, as well as to look for evidence of eventual transcytosis. Our results show that all of the nanoparticles were internalised, to different extents, by the BBB model and accumulated along the endo-lysosomal pathway. Rare events suggestive of nanoparticle transcytosis were also observed for several of the tested materials.The blood-brain barrier (BBB) is a selective barrier, which controls and limits access to the central nervous system (CNS). The selectivity of the BBB relies on specialized characteristics of the endothelial cells that line the microvasculature, including the expression of intercellular tight junctions, which limit paracellular permeability. Several reports suggest that nanoparticles have a unique capacity to cross the BBB. However, direct evidence of nanoparticle transcytosis is difficult to obtain, and we found that typical transport studies present several limitations when applied to nanoparticles. In

  19. Who needs capacity?

    PubMed

    Buchanan, Alec

    2015-01-01

    The UK Law Commission's Discussion Paper, Criminal Liability: Insanity and Automatism, recommends introducing the concept of capacity to the insanity defence. The concept of capacity has an established role in those parts of the law that concern the validity of the decisions that people make, for instance in composing a will or entering into a contract. Making mental capacity a criterion for criminal responsibility in a mentally disordered defendant, however, is potentially problematic. First, the term capacity already has several different meanings in the literature on the jurisprudence of mental abnormality. Second, using the concept of capacity in the way that the Law Commission proposes poses difficulties that relate to the provision of testimony by expert witnesses.

  20. Who needs capacity?

    PubMed

    Buchanan, Alec

    2015-01-01

    The UK Law Commission's Discussion Paper, Criminal Liability: Insanity and Automatism, recommends introducing the concept of capacity to the insanity defence. The concept of capacity has an established role in those parts of the law that concern the validity of the decisions that people make, for instance in composing a will or entering into a contract. Making mental capacity a criterion for criminal responsibility in a mentally disordered defendant, however, is potentially problematic. First, the term capacity already has several different meanings in the literature on the jurisprudence of mental abnormality. Second, using the concept of capacity in the way that the Law Commission proposes poses difficulties that relate to the provision of testimony by expert witnesses. PMID:25939285

  1. Peptide-modified zwitterionic porous hydrogels for endothelial cell and vascular engineering.

    PubMed

    Lin, Chih-Yeh; Wang, Yi-Ren; Lin, Che-Wei; Wang, Shih-Wen; Chien, Hsiu-Wen; Cheng, Nai-Chen; Tsai, Wei-Bor; Yu, Jiashing

    2014-12-01

    Hydrogels allow control of gel composition and mechanics, and permit incorporation of cells and a wide variety of molecules from nanoparticles to micromolecules. Peptide-linked hydrogels should tune the basic polymer into a more bioactive template to influence cellular activities. In this study, we first introduced the generation of 2D poly-(sulfobetaine methacrylate [SBMA]) hydrogel surfaces. By incorporating with functional peptide RGD and vascular endothelial growth factor-mimicking peptide KLTWQELYQLKYKG (QK) peptides, endothelial cells attached to the surface well and proliferated in a short-term culturing. However, the mechanical property, which plays a crucial role directing the cellular functions and supporting the structures, decreased when peptides graft onto hydrogels. Manipulating the mechanical property was thus necessary, and the most related factor was the monomer concentration. From our results, the higher amount of SBMA caused greater stiffness in hydrogels. Following the 2D surface studies, we fabricated 3D porous hydrogels for cell scaffolds by several methods. The salt/particle leaching method showed a more reliable way than gas-foaming method to fabricate homogeneous and open-interconnected pores within the hydrogel. Using the salt/particle leaching method, we can control the pore size before leaching. Morphology of endothelial cells within scaffolds was also investigated by scanning electron microscopy, and histological analysis was conducted in vitro and in vivo to test the biocompatibility of SB hydrogel and its potential as a therapeutic reagent for ischemic tissue repair in mice. PMID:25469315

  2. Peptide-Modified Zwitterionic Porous Hydrogels for Endothelial Cell and Vascular Engineering

    PubMed Central

    Lin, Chih-Yeh; Wang, Yi-Ren; Lin, Che-Wei; Wang, Shih-Wen; Chien, Hsiu-Wen; Cheng, Nai-Chen; Tsai, Wei-Bor

    2014-01-01

    Abstract Hydrogels allow control of gel composition and mechanics, and permit incorporation of cells and a wide variety of molecules from nanoparticles to micromolecules. Peptide-linked hydrogels should tune the basic polymer into a more bioactive template to influence cellular activities. In this study, we first introduced the generation of 2D poly-(sulfobetaine methacrylate [SBMA]) hydrogel surfaces. By incorporating with functional peptide RGD and vascular endothelial growth factor-mimicking peptide KLTWQELYQLKYKG (QK) peptides, endothelial cells attached to the surface well and proliferated in a short-term culturing. However, the mechanical property, which plays a crucial role directing the cellular functions and supporting the structures, decreased when peptides graft onto hydrogels. Manipulating the mechanical property was thus necessary, and the most related factor was the monomer concentration. From our results, the higher amount of SBMA caused greater stiffness in hydrogels. Following the 2D surface studies, we fabricated 3D porous hydrogels for cell scaffolds by several methods. The salt/particle leaching method showed a more reliable way than gas-foaming method to fabricate homogeneous and open-interconnected pores within the hydrogel. Using the salt/particle leaching method, we can control the pore size before leaching. Morphology of endothelial cells within scaffolds was also investigated by scanning electron microscopy, and histological analysis was conducted in vitro and in vivo to test the biocompatibility of SB hydrogel and its potential as a therapeutic reagent for ischemic tissue repair in mice. PMID:25469315

  3. Hyperbaric oxygen induces a cytoprotective and angiogenic response in human microvascular endothelial cells.

    PubMed

    Godman, Cassandra A; Chheda, Kousanee P; Hightower, Lawrence E; Perdrizet, George; Shin, Dong-Guk; Giardina, Charles

    2010-07-01

    A genome-wide microarray analysis of gene expression was carried out on human microvascular endothelial cells (HMEC-1) exposed to hyperbaric oxygen treatment (HBOT) under conditions that approximated clinical settings. Highly up-regulated genes included immediate early transcription factors (FOS, FOSB, and JUNB) and metallothioneins. Six molecular chaperones were also up-regulated immediately following HBOT, and all of these have been implicated in protein damage control. Pathway analysis programs identified the Nrf-2-mediated oxidative stress response as one of the primary responders to HBOT. Several of the microarray changes in the Nrf2 pathway and a molecular chaperone were validated using quantitative PCR. For all of the genes tested (Nrf2, HMOX1, HSPA1A, M1A, ACTC1, and FOS), HBOT elicited large responses, whereas changes were minimal following treatment with 100% O(2) in the absence of elevated pressure. The increased expression of immediate early and cytoprotective genes corresponded with an HBOT-induced increase in cell proliferation and oxidative stress resistance. In addition, HBOT treatment enhanced endothelial tube formation on Matrigel plates, with particularly dramatic effects observed following two daily HBO treatments. Understanding how HBOT influences gene expression changes in endothelial cells may be beneficial for improving current HBOT-based wound-healing protocols. These data also point to other potential HBOT applications where stimulating protection and repair of the endothelium would be beneficial, such as patient preconditioning prior to major surgery.

  4. Hyperglycaemia exerts deleterious effects on late endothelial progenitor cell secretion actions.

    PubMed

    Zhang, Jie; Zhang, Xiaoyun; Li, Hong; Cui, Xiaodong; Guan, Xiumei; Tang, Kexin; Jin, Chengwen; Cheng, Min

    2013-01-01

    Endothelial progenitor cells (EPCs) play a fundamental role in tissue regeneration and vascular repair both by differentiating into endothelial cells and by secretion of vasoactive substances that promote angiogenesis and maintain vascular homeostasis. It has previously been shown that hyperglycaemia impairs early and late EPC functions, such as differentiation, proliferation and adhesion. However, its role in the regulation of the production of vasoactive substances in EPCs, especially in late EPCs, is less well defined. We investigated the effects of hyperglycaemia on the production of vasodilator, fibrinolytic and angiogenic growth factors, and also on the activity of superoxide dismutase (SOD) in late EPCs. For this purpose, late EPCs were incubated with different concentrations of D-glucose (5-40 mmol/L) for 24 hr. Levels of nitric oxide (NO), tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), prostaglandin I(2) (PGI(2)), vascular endothelial growth factor (VEGF) and the activity of SOD were measured by enzyme-linked immunosorbent assay (ELISA). Under high glucose stress conditions, late EPCs exhibited lower levels of NO, t-PA, PAI-1, PGI(2) and VEGF compared to control medium (5 mmol/L glucose). Moreover, high glucose was also observed to decrease the activity of SOD in late EPCs. These results suggest that hyperglycaemia-induced impairment of late EPC secretion functions could contribute to the development of vascular disease in diabetes.

  5. Surface-modified hyaluronic acid hydrogels to capture endothelial progenitor cells.

    PubMed

    Camci-Unal, Gulden; Aubin, Hug; Ahari, Amirhossein Farajzadeh; Bae, Hojae; Nichol, Jason William; Khademhosseini, Ali

    2010-10-21

    A major challenge to the effective treatment of injured cardiovascular tissues is the promotion of endothelialization of damaged tissues and implanted devices. For this reason, there is a need for new biomaterials that promote endothelialization to enhance vascular repair. The goal of this work was to develop antibody-modified polysaccharide-based hydrogels that could selectively capture endothelial progenitor cells (EPCs). We showed that CD34 antibody immobilization on hyaluronic acid (HA) hydrogels provides a suitable surface to capture EPCs. The effect of CD34 antibody immobilization on EPC adhesion was found to be dependent on antibody concentration. The highest level of EPC attachment was found to be 52.2 cells per mm(2) on 1% HA gels modified with 25 μg mL(-1) antibody concentration. Macrophages did not exhibit significant attachment on these modified hydrogel surfaces compared to the EPCs, demonstrating the selectivity of the system. Hydrogels containing only HA, with or without immobilized CD34, did not allow for spreading of EPCs 48 h after cell seeding, even though the cells were adhered to the hydrogel surface. To promote spreading of EPCs, 2% (w/v) gelatin methacrylate (GelMA) containing HA hydrogels were synthesized and shown to improve cell spreading and elongation. This strategy could potentially be useful to enhance the biocompatibility of implants such as artificial heart valves or in other tissue engineering applications where formation of vascular structures is required.

  6. Endocarditis and Incomplete Endothelialization 12 Years after Amplatzer Septal Occluder Deployment.

    PubMed

    Nguyen, Allan K; Palafox, Brian A; Starr, Joanne P; Gates, Richard N; Berdjis, Farbouch

    2016-06-01

    A 4-year-old boy had a 15-mm atrial septal defect repaired percutaneously with use of an Amplatzer Septal Occluder. At age 16 years, he presented with a week's history of fever, chills, dyspnea, fatigue, and malaise. Cultures grew methicillin-sensitive Staphylococcus aureus. A transesophageal echocardiogram showed a 1.25 × 1.5-cm pedunculated mass on the left aspect of the atrial septum just superior to the mitral valve, and a smaller vegetation on the right inferior medial aspect of the septum. At surgery, visual examination of both sides of the septum revealed granulation tissue, the pedunculated mass, the small vegetation, and exposed metal wires that suggested incomplete endothelialization of the occluder. We removed the occluder and patched the septal defect. The patient returned to full activity after 4 months and was asymptomatic 3 years postoperatively. Our report reinforces the need for further investigation into prosthetic device endothelialization, endocarditis prophylaxis, and recommended levels of physical activity in patients whose devices might be incompletely endothelialized. In addition to reporting our patient's case, we review the medical literature on this topic. PMID:27303238

  7. Endocarditis and Incomplete Endothelialization 12 Years after Amplatzer Septal Occluder Deployment

    PubMed Central

    Nguyen, Allan K.; Starr, Joanne P.; Gates, Richard N.; Berdjis, Farbouch

    2016-01-01

    A 4-year-old boy had a 15-mm atrial septal defect repaired percutaneously with use of an Amplatzer Septal Occluder. At age 16 years, he presented with a week's history of fever, chills, dyspnea, fatigue, and malaise. Cultures grew methicillin-sensitive Staphylococcus aureus. A transesophageal echocardiogram showed a 1.25 × 1.5-cm pedunculated mass on the left aspect of the atrial septum just superior to the mitral valve, and a smaller vegetation on the right inferior medial aspect of the septum. At surgery, visual examination of both sides of the septum revealed granulation tissue, the pedunculated mass, the small vegetation, and exposed metal wires that suggested incomplete endothelialization of the occluder. We removed the occluder and patched the septal defect. The patient returned to full activity after 4 months and was asymptomatic 3 years postoperatively. Our report reinforces the need for further investigation into prosthetic device endothelialization, endocarditis prophylaxis, and recommended levels of physical activity in patients whose devices might be incompletely endothelialized. In addition to reporting our patient's case, we review the medical literature on this topic. PMID:27303238

  8. Aberrant repair and fibrosis development in skeletal muscle

    PubMed Central

    2011-01-01

    The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells and resident stem cells orchestrate their activities to restore tissue homeostasis. However, during chronic tissue damage, such as in muscular dystrophies, the inflammatory-cell infiltration and fibroblast activation persists, while the reparative capacity of stem cells (satellite cells) is attenuated. Abnormal dystrophic muscle repair and its end stage, fibrosis, represent the final common pathway of virtually all chronic neurodegenerative muscular diseases. As our understanding of the pathogenesis of muscle fibrosis has progressed, it has become evident that the muscle provides a useful model for the regulation of tissue repair by the local microenvironment, showing interplay among muscle-specific stem cells, inflammatory cells, fibroblasts and extracellular matrix components of the mammalian wound-healing response. This article reviews the emerging findings of the mechanisms that underlie normal versus aberrant muscle-tissue repair. PMID:21798099

  9. p53 downregulates the Fanconi anaemia DNA repair pathway

    PubMed Central

    Jaber, Sara; Toufektchan, Eléonore; Lejour, Vincent; Bardot, Boris; Toledo, Franck

    2016-01-01

    Germline mutations affecting telomere maintenance or DNA repair may, respectively, cause dyskeratosis congenita or Fanconi anaemia, two clinically related bone marrow failure syndromes. Mice expressing p53Δ31, a mutant p53 lacking the C terminus, model dyskeratosis congenita. Accordingly, the increased p53 activity in p53Δ31/Δ31 fibroblasts correlated with a decreased expression of 4 genes implicated in telomere syndromes. Here we show that these cells exhibit decreased mRNA levels for additional genes contributing to telomere metabolism, but also, surprisingly, for 12 genes mutated in Fanconi anaemia. Furthermore, p53Δ31/Δ31 fibroblasts exhibit a reduced capacity to repair DNA interstrand crosslinks, a typical feature of Fanconi anaemia cells. Importantly, the p53-dependent downregulation of Fanc genes is largely conserved in human cells. Defective DNA repair is known to activate p53, but our results indicate that, conversely, an increased p53 activity may attenuate the Fanconi anaemia DNA repair pathway, defining a positive regulatory feedback loop. PMID:27033104

  10. Dorsal variant blister aneurysm repair.

    PubMed

    Couldwell, William T; Chamoun, Roukoz

    2012-01-01

    Dorsal variant proximal carotid blister aneurysms are treacherous lesions to manage. It is important to recognize this variant on preoperative angiographic imaging, in anticipation of surgical strategies for their treatment. Strategies include trapping the involved segment and revascularization if necessary. Other options include repair of the aneurysm rupture site directly. Given that these are not true berry aneurysms, repair of the rupture site involves wrapping or clip-grafting techniques. The case presented here was a young woman with a subarachnoid hemorrhage from a ruptured dorsal variant blister aneurysm. The technique used is demonstrated in the video and is a modified clip-wrap technique using woven polyester graft material. The patient was given aspirin preoperatively as preparation for the clip-wrap technique. It is the authors' current protocol to attempt a direct repair with clip-wrapping and leaving artery sacrifice with or without bypass as a salvage therapy if direct repair is not possible. Assessment of vessel patency after repair is performed by intraoperative Doppler and indocyanine green angiography. Intraoperative somatosensory and motor evoked potential monitoring is performed in all cases. The video can be found here: http://youtu.be/crUreWGQdGo.

  11. Reprogramming Cells for Brain Repair

    PubMed Central

    Guarino, Alyx T.; McKinnon, Randall D.

    2013-01-01

    At present there are no clinical therapies that can repair traumatic brain injury, spinal cord injury or degenerative brain disease. While redundancy and rewiring of surviving circuits can recover some lost function, the brain and spinal column lack sufficient endogenous stem cells to replace lost neurons or their supporting glia. In contrast, pre-clinical studies have demonstrated that exogenous transplants can have remarkable efficacy for brain repair in animal models. Mesenchymal stromal cells (MSCs) can provide paracrine factors that repair damage caused by ischemic injury, and oligodendrocyte progenitor cell (OPC) grafts give dramatic functional recovery from spinal cord injury. These studies have progressed to clinical trials, including human embryonic stem cell (hESC)-derived OPCs for spinal cord repair. However, ESC-derived allografts are less than optimal, and we need to identify a more appropriate donor graft population. The cell reprogramming field has developed the ability to trans-differentiate somatic cells into distinct cell types, a technology that has the potential to generate autologous neurons and glia which address the histocompatibility concerns of allografts and the tumorigenicity concerns of ESC-derived grafts. Further clarifying how cell reprogramming works may lead to more efficient direct reprogram approaches, and possibly in vivo reprogramming, in order to promote brain and spinal cord repair. PMID:24961526

  12. Essentials of skin laceration repair.

    PubMed

    Forsch, Randall T

    2008-10-15

    Skin laceration repair is an important skill in family medicine. Sutures, tissue adhesives, staples, and skin-closure tapes are options in the outpatient setting. Physicians should be familiar with various suturing techniques, including simple, running, and half-buried mattress (corner) sutures. Although suturing is the preferred method for laceration repair, tissue adhesives are similar in patient satisfaction, infection rates, and scarring risk in low skin-tension areas and may be more cost-effective. The tissue adhesive hair apposition technique also is effective in repairing scalp lacerations. The sting of local anesthesia injections can be lessened by using smaller gauge needles, administering the injection slowly, and warming or buffering the solution. Studies have shown that tap water is safe to use for irrigation, that white petrolatum ointment is as effective as antibiotic ointment in postprocedure care, and that wetting the wound as early as 12 hours after repair does not increase the risk of infection. Patient education and appropriate procedural coding are important after the repair. PMID:18953970

  13. Buyanghuanwu decoction promotes angiogenesis after cerebral ischemia/reperfusion injury: mechanisms of brain tissue repair

    PubMed Central

    Zhang, Zhen-qiang; Song, Jun-ying; Jia, Ya-quan; Zhang, Yun-ke

    2016-01-01

    Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically given Buyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. In rats administered Buyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrin αvβ3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days). These data suggest that Buyanghuanwu decoction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury. PMID:27127482

  14. The isolation and culture of endothelial colony-forming cells from human and rat lungs.

    PubMed

    Alphonse, Rajesh S; Vadivel, Arul; Zhong, Shumei; Zong, Shumei; McConaghy, Suzanne; Ohls, Robin; Yoder, Mervin C; Thébaud, Bernard

    2015-11-01

    Blood vessels are crucial for the normal development, lifelong repair and homeostasis of tissues. Recently, vascular progenitor cell-driven 'postnatal vasculogenesis' has been suggested as an important mechanism that contributes to new blood vessel formation and organ repair. Among several described progenitor cell types that contribute to blood vessel formation, endothelial colony-forming cells (ECFCs) have received widespread attention as lineage-specific 'true' vascular progenitors. Here we describe a protocol for the isolation of pulmonary microvascular ECFCs from human and rat lung tissue. Our technique takes advantage of an earlier protocol for the isolation of circulating ECFCs from the mononuclear cellular fraction of peripheral blood. We adapted the earlier protocol to isolate resident ECFCs from the distal lung tissue. After enzymatic dispersion of rat or human lung samples into a cellular suspension, CD31-expressing cells are positively selected using magnetic-activated cell sorting and plated in endothelial-specific growth conditions. The colonies arising after 1-2 weeks in culture are carefully separated and expanded to yield pure ECFC cultures after a further 2-3 weeks. The resulting cells demonstrate the defining characteristics of ECFCs such as (i) 'cobblestone' morphology of cultured cell monolayers; (ii) acetylated low-density lipoprotein uptake and Ulex europaeus lectin binding; (iii) tube-like network formation in Matrigel; (iv) expression of endothelial cell-specific surface markers and the absence of hematopoietic or myeloid surface antigens; (v) self-renewal potential displayed by the most proliferative cells; and (vi) contribution to de novo vessel formation in an in vivo mouse implant model. Assuming typical initial cell adhesion and proliferation rates, the entire procedure can be completed within 4 weeks. Isolation and culture of lung vascular ECFCs will allow assessment of the functional state of these cells in experimental and human

  15. The isolation and culture of endothelial colony-forming cells from human and rat lungs.

    PubMed

    Alphonse, Rajesh S; Vadivel, Arul; Zhong, Shumei; Zong, Shumei; McConaghy, Suzanne; Ohls, Robin; Yoder, Mervin C; Thébaud, Bernard

    2015-11-01

    Blood vessels are crucial for the normal development, lifelong repair and homeostasis of tissues. Recently, vascular progenitor cell-driven 'postnatal vasculogenesis' has been suggested as an important mechanism that contributes to new blood vessel formation and organ repair. Among several described progenitor cell types that contribute to blood vessel formation, endothelial colony-forming cells (ECFCs) have received widespread attention as lineage-specific 'true' vascular progenitors. Here we describe a protocol for the isolation of pulmonary microvascular ECFCs from human and rat lung tissue. Our technique takes advantage of an earlier protocol for the isolation of circulating ECFCs from the mononuclear cellular fraction of peripheral blood. We adapted the earlier protocol to isolate resident ECFCs from the distal lung tissue. After enzymatic dispersion of rat or human lung samples into a cellular suspension, CD31-expressing cells are positively selected using magnetic-activated cell sorting and plated in endothelial-specific growth conditions. The colonies arising after 1-2 weeks in culture are carefully separated and expanded to yield pure ECFC cultures after a further 2-3 weeks. The resulting cells demonstrate the defining characteristics of ECFCs such as (i) 'cobblestone' morphology of cultured cell monolayers; (ii) acetylated low-density lipoprotein uptake and Ulex europaeus lectin binding; (iii) tube-like network formation in Matrigel; (iv) expression of endothelial cell-specific surface markers and the absence of hematopoietic or myeloid surface antigens; (v) self-renewal potential displayed by the most proliferative cells; and (vi) contribution to de novo vessel formation in an in vivo mouse implant model. Assuming typical initial cell adhesion and proliferation rates, the entire procedure can be completed within 4 weeks. Isolation and culture of lung vascular ECFCs will allow assessment of the functional state of these cells in experimental and human

  16. Calreticulin Enhances Porcine Wound Repair by Diverse Biological Effects

    PubMed Central

    Nanney, Lillian B.; Woodrell, Christopher D.; Greives, Mathew R.; Cardwell, Nancy L.; Pollins, Alonda C.; Bancroft, Tara A.; Chesser, Adrianne; Michalak, Marek; Rahman, Mohammad; Siebert, John W.; Gold, Leslie I.

    2008-01-01

    Extracellular functions of the endoplasmic reticulum chaperone protein calreticulin (CRT) are emerging. Here we show novel roles for exogenous CRT in both cutaneous wound healing and diverse processes associated with repair. Compared with platelet-derived growth factor-BB-treated controls, topical application of CRT to porcine excisional wounds enhanced the rate of wound re-epithelialization. In both normal and steroid-impaired pigs, CRT increased granulation tissue formation. Immunohistochemical analyses of the wounds 5 and 10 days after injury revealed marked up-regulation of transforming growth factor-β3 (a key regulator of wound healing), a threefold increase in macrophage influx, and an increase in the cellular proliferation of basal keratinocytes of the new epidermis and of cells of the neodermis. In vitro studies confirmed that CRT induced a greater than twofold increase in the cellular proliferation of primary human keratinocytes, fibroblasts, and microvascular endothelial cells (with 100 pg/ml, 100 ng/ml, and 1.0 pg/ml, respectively). Moreover, using a scratch plate assay, CRT maximally induced the cellular migration of keratinocytes and fibroblasts (with 10 pg/ml and 1 ng/ml, respectively). In addition, CRT induced concentration-dependent migration of keratinocytes, fibroblasts macrophages, and monocytes in chamber assays. These in vitro bioactivities provide mechanistic support for the positive biological effects of CRT observed on both the epidermis and dermis of wounds in vivo, underscoring a significant role for CRT in the repair of cutaneous wounds. PMID:18753412

  17. Single-cell microarray enables high-throughput evaluation of DNA double-strand breaks and DNA repair inhibitors

    PubMed Central

    Weingeist, David M.; Ge, Jing; Wood, David K.; Mutamba, James T.; Huang, Qiuying; Rowland, Elizabeth A.; Yaffe, Michael B.; Floyd, Scott; Engelward, Bevin P.

    2013-01-01

    A key modality of non-surgical cancer management is DNA damaging therapy that causes DNA double-strand breaks that are preferentially toxic to rapidly dividing cancer cells. Double-strand break repair capacity is recognized as an important mechanism in drug resistance and is therefore a potential target for adjuvant chemotherapy. Additionally, spontaneous and environmentally induced DSBs are known to promote cancer, making DSB evaluation important as a tool in epidemiology, clinical evaluation and in the development of novel pharmaceuticals. Currently available assays to detect double-strand breaks are limited in throughput and specificity and offer minimal information concerning the kinetics of repair. Here, we present the CometChip, a 96-well platform that enables assessment of double-strand break levels and repair capacity of multiple cell types and conditions in parallel and integrates with standard high-throughput screening and analysis technologies. We demonstrate the ability to detect multiple genetic deficiencies in double-strand break repair and evaluate a set of clinically relevant chemical inhibitors of one of the major double-strand break repair pathways, non-homologous end-joining. While other high-throughput repair assays measure residual damage or indirect markers of damage, the CometChip detects physical double-strand breaks, providing direct measurement of damage induction and repair capacity, which may be useful in developing and implementing treatment strategies with reduced side effects. PMID:23422001

  18. Radioligand binding to muscarinic receptors of bovine aortic endothelial cells.

    PubMed Central

    Brunner, F.; Kukovetz, W. R.

    1991-01-01

    1. Muscarinic receptors on endothelial cells of bovine thoracic aorta were characterized by binding assays in which (-)-[3H]-N-methyl quinuclidinyl benzilate ([3H]-NMeQNB) was used as radioligand. 2. Binding of [3H]-NMeQNB to crude membranes of freshly isolated endothelial cells was atropine-displaceable and of high affinity (KD = 0.48 nM) to a single class of sites (maximum binding capacity: 14 +/- 3 fmol mg-1 protein). Stereospecificity of the binding sites was demonstrated in experiments in which [3H]-NMeQNB binding was inhibited by dexetimide in the nanomolar range (KI = 0.63 nM) and by levetimide, its stereoisomer in the micromolar range (KI = 3.2 microM) (selectivity factor: approximately 5000). 3. Drug competition curves indicated a single class of binding sites for antagonists and the following apparent affinities (KI, nM): methyl atropine: 1.1: 4-diphenylacetoxy N-methyl piperidine methyl bromide (4-DAMP): 3.4; pirenzepine: 16; 11-[2-diethylamino-methyl)-1-piperidinyl- acetyl]-5,11-dihydro-6H-pyrido(2,3-b)1,4-benzodiazepine-6-one (AF-DX 116); 2.500. Competition of acetylcholine with [3H]-NMeQNB was best described by two affinity sites (or states) (KH = 0.82 microM, KL = 1.6 microM). In the presence of guanylimido diphosphate [Gpp(NH)p] (100 microM), acetylcholine affinity (IC50) was slightly, but significantly reduced (factor approximately 4). 4. Binding of [3H]-NMeQNB to freshly harvested intact cells was also atropine-displaceable, stereospecific (selectivity factor: approximately 3500) and of high affinity (KD = 0.35 nM). The maximum binding capacity (9 +/- 2 fmol mg-1 total cell protein) was comparable to that of membranes and corresponded to approximately 900 binding sites per endothelial cell.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2015420

  19. Vascular endothelial growth factor B, a novel growth factor for endothelial cells.

    PubMed Central

    Olofsson, B; Pajusola, K; Kaipainen, A; von Euler, G; Joukov, V; Saksela, O; Orpana, A; Pettersson, R F; Alitalo, K; Eriksson, U

    1996-01-01

    We have isolated and characterized a novel growth factor for endothelial cells, vascular endothelial growth factor B (VEGF-B), with structural similarities to vascular endothelial growth factor (VEGF) and placenta growth factor. VEGF-B was particularly abundant in heart and skeletal muscle and was coexpressed with VEGF in these and other tissues. VEGF-B formed cell-surface-associated disulfide-linked homodimers and heterodimerized with VEGF when coexpressed. Conditioned medium from transfected 293EBNA cells expressing VEGF-B stimulated DNA synthesis in endothelial cells. Our results suggest that VEGF-B has a role in angiogenesis and endothelial cell growth, particularly in muscle. Images Fig. 3 Fig. 4 Fig. 5 PMID:8637916

  20. Cardiorespiratory responses to exercise after anatomic repair of atrioventricular discordance with abnormal ventriculoarterial connection.

    PubMed

    Yasuda, Kenji; Ohuchi, Hideo; Ono, Yasuo; Yagihara, Toshikatsu; Echigo, Shigeyuki

    2007-01-01

    We evaluated exercise tolerance and cardiorespiratory responses to exercise in patients with atrioventricular discordance (AVD) and abnormal ventriculoarterial connection after anatomic repair. Cardiopulmonary treadmill exercise testing with gas measurement was done 62 times in 19 patients with AVD who had undergone anatomic repair at the National Cardiovascular Center. Exercise duration, oxygen uptake (V(O2)) and heart rate at anaerobic threshold and peak, and oxygen pulse during exercise were significantly lower in patients with AVD after anatomic repair than in controls. Carbon dioxide ventilatory equivalent during exercise was worse in patients with AVD after anatomic repair than in controls. Percentage peak V(O2) significantly correlated positively with percentage peak oxygen pulse and tended to correlate positively with the heart rate increments. Patients with AVD after anatomic repair exhibit impaired responses of heart rate and oxygen pulse with lower exercise capacity. Careful attention should be paid to patients with AVD after anatomic repair in terms of their functional capacity as well as other postoperative complications.

  1. Oxidized low-density lipoprotein alters the effect of matrix stiffness on the formation of endothelial networks and capillary lumens

    PubMed Central

    2013-01-01

    Abstract Formation of new blood vessels is essential for vascular repair and remodeling, and it is known that biomechanical properties of extracellular matrix play a major role in this process. Our earlier studies have also shown that exposing endothelial cells to oxidized modification of low-density lipoproteins (oxLDL) increases endothelial stiffness and facilitates their ability to form cellular networks, suggesting that it facilitates endothelial angiogenic potential. The goal of this study, therefore, was to test the interrelationship between matrix stiffness and oxLDL in the regulation of angiogenesis. Our results show that, as expected, an increase in matrix stiffness inhibited endothelial network formation and that exposure to oxLDL significantly facilitated this process. We also show, however, that oxLDL-induced facilitation of endothelial networks was observed only in stiff (3 mg/mL) but not in soft (1 mg/mL) collagen gels, resulting in blunting the effect of matrix stiffness. Also unexpectedly, we show that an increase in matrix stiffness results in a significant increase in the number of capillary lumens that are formed by single cells or pairs of cells, suggesting that while endothelial connectivity is impaired, formation of single-cell lumens is facilitated. oxLDL facilitates lumen formation, but this effect is also matrix dependent and is observed only in soft gels and not in stiff gels. Finally, an increase in both matrix stiffness and oxLDL exposure results in changes in capillary morphology, with the formation of larger capillary lumens. Overall, our study suggests that oxLDL plays an important role in formation of new capillaries and their morphology and that this effect is critically dependent on the extracellular environment’s compliance, thereby underlining the importance of the interdependence of these parameters. PMID:24618546

  2. Oxidized low-density lipoprotein alters the effect of matrix stiffness on the formation of endothelial networks and capillary lumens.

    PubMed

    Gundavaram, Madhu S; Shentu, Tzu Pin; Kowalsky, Gregory B; Volkov, Suncica; Schraufnagel, Dean E; Levitan, Irena

    2013-09-01

    Abstract Formation of new blood vessels is essential for vascular repair and remodeling, and it is known that biomechanical properties of extracellular matrix play a major role in this process. Our earlier studies have also shown that exposing endothelial cells to oxidized modification of low-density lipoproteins (oxLDL) increases endothelial stiffness and facilitates their ability to form cellular networks, suggesting that it facilitates endothelial angiogenic potential. The goal of this study, therefore, was to test the interrelationship between matrix stiffness and oxLDL in the regulation of angiogenesis. Our results show that, as expected, an increase in matrix stiffness inhibited endothelial network formation and that exposure to oxLDL significantly facilitated this process. We also show, however, that oxLDL-induced facilitation of endothelial networks was observed only in stiff (3 mg/mL) but not in soft (1 mg/mL) collagen gels, resulting in blunting the effect of matrix stiffness. Also unexpectedly, we show that an increase in matrix stiffness results in a significant increase in the number of capillary lumens that are formed by single cells or pairs of cells, suggesting that while endothelial connectivity is impaired, formation of single-cell lumens is facilitated. oxLDL facilitates lumen formation, but this effect is also matrix dependent and is observed only in soft gels and not in stiff gels. Finally, an increase in both matrix stiffness and oxLDL exposure results in changes in capillary morphology, with the formation of larger capillary lumens. Overall, our study suggests that oxLDL plays an important role in formation of new capillaries and their morphology and that this effect is critically dependent on the extracellular environment's compliance, thereby underlining the importance of the interdependence of these parameters.

  3. Modulation of endothelial cell phenotype by physical activity: impact on obesity-related endothelial dysfunction.

    PubMed

    Bender, Shawn B; Laughlin, M Harold

    2015-07-01

    Increased levels of physical activity are associated with reduced cardiovascular disease (CVD) risk and mortality in obesity and diabetes. Available evidence suggests that local factors, including local hemodynamics, account for a significant portion of this CVD protection, and numerous studies have interrogated the therapeutic benefit of physical activity/exercise training in CVD. Less well established is whether basal differences in endothelial cell phenotype between/among vasculatures related to muscle recruitment patterns during activity may account for reports of nonuniform development of endothelial dysfunction in obesity. This is the focus of this review. We highlight recent work exploring the vulnerability of two distinct vasculatures with established differences in endothelial cell phenotype. Specifically, based largely on dramatic differences in underlying hemodynamics, arteries perfusing soleus muscle (slow-twitch muscle fibers) and those perfusing gastrocnemius muscle (fast-twitch muscle fibers) in the rat exhibit an exercise training-like versus an untrained endothelial cell phenotype, respectively. In the context of obesity, therefore, arteries to soleus muscle exhibit protection from endothelial dysfunction compared with vulnerable arteries to gastrocnemius muscle. This disparate vulnerability is consistent with numerous animal and human studies, demonstrating increased skeletal muscle blood flow heterogeneity in obesity coincident with reduced muscle function and exercise intolerance. Mechanistically, we highlight emerging areas of inquiry exploring novel aspects of hemodynamic-sensitive signaling in endothelial cells and the time course of physical activity-associated endothelial adaptations. Lastly, further exploration needs to consider the impact of endothelial heterogeneity on the development of endothelial dysfunction because endothelial dysfunction independently predicts CVD events.

  4. Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought induces xylem embolism formation, but grapevines can refill blocked conduits to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analyzed in vivo embolism formation and repair using x-ray microtomog...

  5. Practical aspects of coating repair

    SciTech Connect

    Munger, C.G.

    1980-02-01

    Detailed information is given concerning the types of coatings failures that are amenable to repair and materials and methods effective in making them. Coatings failure types are analyzed, and recommended surface preparation for several types of failure are described in detail. Consequences of improper surface preparation are emphasized. Precautions necessary for selection of materials and for application methods effective in applying coatings over old coatings are presented in detail. Characteristics and causes are given for pinpoint rusting, delamination, chalking, and undercutting by rust. Characteristics and causes of gas and liquid blisters are described and methods of repairing coating underneath them are detailed. Special attention is given to repairs on galvanizing and inorganic zinc-loaded coatings and the correct procedures of surface preparation and overcoating. Importance of time after start of failure to begin recoating is emphasized.

  6. Endothelial adhesion receptors are recruited to adherent leukocytes by inclusion in preformed tetraspanin nanoplatforms

    PubMed Central

    Barreiro, Olga; Zamai, Moreno; Yáñez-Mó, María; Tejera, Emilio; López-Romero, Pedro; Monk, Peter N.; Gratton, Enrico; Caiolfa, Valeria R.; Sánchez-Madrid, Francisco

    2008-01-01

    VCAM-1 and ICAM-1, receptors for leukocyte integrins, are recruited to cell–cell contact sites on the apical membrane of activated endothelial cells. In this study, we show that this recruitment is independent of ligand engagement, actin cytoskeleton anchorage, and heterodimer formation. Instead, VCAM-1 and ICAM-1 are recruited by inclusion within specialized preformed tetraspanin-enriched microdomains, which act as endothelial adhesive platforms (EAPs). Using advanced analytical fluorescence techniques, we have characterized the diffusion properties at the single-molecule level, nanoscale organization, and specific intradomain molecular interactions of EAPs in living primary endothelial cells. This study provides compelling evidence for the existence of EAPs as physical entities at the plasma membrane, distinct from lipid rafts. Scanning electron microscopy of immunogold-labeled samples treated with a specific tetraspanin-blocking peptide identify nanoclustering of VCAM-1 and ICAM-1 within EAPs as a novel mechanism for supramolecular organization that regulates the leukocyte integrin–binding capacity of both endothelial receptors during extravasation. PMID:18955551

  7. Toxic effects of iron oxide nanoparticles on human umbilical vein endothelial cells.

    PubMed

    Wu, Xinying; Tan, Yanbin; Mao, Hui; Zhang, Minming

    2010-01-01

    Iron oxide nanoparticles (IONPs) have been employed for hyperthermia treatments, stem cell therapies, cell labeling, and imaging modalities. The biocompatibility and cytotoxic effects of iron oxide nanoparticles when used in biomedical applications, however, are an ongoing concern. Endothelial cells have a critical role in this research dealing with tumors, cardiovascular disease and inflammation. However, there is little information dealing with the biologic effects of IONPs on the endothelial cell. This paper deals with the influence of dextran and citric acid coated IONPs on the behavior and function of human umbilical vein endothelial cells (HUVECs). After exposing endothelial cells to IONPs, dose-dependent effects on HUVECs viability, cytoskeleton and function were determined. Both citric acid and dextran coated particles appeared to be largely internalized by HUVECs through endocytosis and contribute to eventual cell death possibly by apoptosis. Cytoskeletal structures were greatly disrupted, as evidenced by diminished vinculin spots, and disorganized actin fiber and tubulin networks. The capacity of HUVECs to form a vascular network on Matrigel™ diminished after exposure to IONPs. Cell migration/invasion were inhibited significantly even at very low iron concentrations (0.1 mM). The results of this study indicate the great importance of thoroughly understanding nanoparticle-cell interactions, and the potential to exploit this understanding in tumor therapy applications involving IONPs as thermo/chemoembolization agents.

  8. Cathepsin B Regulates the Intrinsic Angiogenic Threshold of Endothelial CellsD⃞

    PubMed Central

    Im, Eunok; Venkatakrishnan, Annapurna; Kazlauskas, Andrius

    2005-01-01

    The lysosomal protease cathepsin B has been implicated in a variety of pathologies including pancreatitis, tumor angiogenesis, and neuronal diseases. We used a tube formation assay to investigate the role of cathepsin B in angiogenesis. When cultured between two layers of collagen I, primary endothelial cells formed tubes in response to exogenously added VEGF. Overexpressing cathepsin B reduced the VEGF-dependent tube response, whereas pharmacologically or molecularly suppressing cathepsin B eliminated the dependence on exogenous VEGF. However, tube formation still required VEGF receptor activity, which suggested that endothelial cells generated VEGF. Indeed, VEGF mRNA and protein was detectable in cells treated with cathepsin B inhibitor, which correlated with a rise in the level of HIF-1α. In addition to boosting the level of proangiogenic factors, blocking cathepsin B activity reduced the amount of the antiangiogenic protein endostatin. Thus endothelial cells have the intrinsic capacity to generate pro- and antiangiogenic agents. These observations complement and expand our appreciation of how endothelial cell–derived proteases regulate angiogenesis. PMID:15901832

  9. Refinery Capacity Report

    EIA Publications

    2016-01-01

    Data series include fuel, electricity, and steam purchased for consumption at the refinery; refinery receipts of crude oil by method of transportation; and current and projected atmospheric crude oil distillation, downstream charge, and production capacities. Respondents are operators of all operating and idle petroleum refineries (including new refineries under construction) and refineries shut down during the previous year, located in the 50 states, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, and other U.S. possessions. The Refinery Capacity Report does not contain working and shell storage capacity data. This data is now being collected twice a year as of March 31 and September 30 on the Form EIA-810, "Monthly Refinery Report", and is now released as a separate report Working and Net Available Shell Storage Capacity.

  10. Knudsen heat capacity

    SciTech Connect

    Babac, Gulru; Reese, Jason M.

    2014-05-15

    We present a “Knudsen heat capacity” as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

  11. Panama Canal capacity analysis

    SciTech Connect

    Bronzini, M.S.

    1995-04-27

    Predicting the transit capacities of the various Panama Canal alternatives required analyzing data on present Canal operations, adapting and extending an existing computer simulation model, performing simulation runs for each of the alternatives, and using the simulation model outputs to develop capacity estimates. These activities are summarized in this paper. A more complete account may be found in the project final report (TAMS 1993). Some of the material in this paper also appeared in a previously published paper (Rosselli, Bronzini, and Weekly 1994).

  12. Techniques in Endovascular Aneurysm Repair

    PubMed Central

    Phade, Sachin V.; Garcia-Toca, Manuel; Kibbe, Melina R.

    2011-01-01

    Endovascular repair of infrarenal abdominal aortic aneurysms (EVARs) has revolutionized the treatment of aortic aneurysms, with over half of elective abdominal aortic aneurysm repairs performed endoluminally each year. Since the first endografts were placed two decades ago, many changes have been made in graft design, operative technique, and management of complications. This paper summarizes modern endovascular grafts, considerations in preoperative planning, and EVAR techniques. Specific areas that are addressed include endograft selection, arterial access, sheath delivery, aortic branch management, graft deployment, intravascular ultrasonography, pressure sensors, management of endoleaks and compressed limbs, and exit strategies. PMID:22121487

  13. Proximal Rectus Femoris Avulsion Repair.

    PubMed

    Dean, Chase S; Arbeloa-Gutierrez, Lucas; Chahla, Jorge; Pascual-Garrido, Cecilia

    2016-06-01

    Proximal rectus femoris tendon avulsions are rare and occur mostly in male athletes. Currently, the standard of care for complete tendinous avulsions of the direct arm of the rectus femoris is nonoperative treatment. However, surgical repair may be considered in high-level athletes who have a high demand for repetitive hip flexion performed in an explosive manner or in patients in whom nonoperative treatment has failed. The purpose of this technical note is to describe the method for surgical repair of the proximal direct arm of the rectus femoris to its origin at the anterior inferior iliac spine using suture anchors. PMID:27656376

  14. Endothelial progenitor cells in diabetic foot syndrome.

    PubMed

    Drela, Ewelina; Stankowska, Katarzyna; Kulwas, Arleta; Rość, Danuta

    2012-01-01

    In the late 20th century endothelial progenitor cells (EPCs) were discovered and identified as cells capable of differentiating into endothelial cells. Antigens characteristic of endothelial cells and hematopoietic cells are located on their surface. EPCs can proliferate, adhere, migrate and have the specific ability to form vascular structure, and they have a wide range of roles: They participate in maintaining hemostasis, and play an important part in the processes of vasculogenesis and angiogenesis. They are sources of angiogenic factors, especially vascular endothelial growth factor (VEGF). EPCs exist in bone marrow, from which they are recruited into circulation in response to specific stimuli. Tissue ischemia is thought to be the strongest inductor of EPC mobilization. Local ischemia accompanies many pathological states, including diabetic foot syndrome (DFS). Impaired angiogenesis--in which EPCs participate--is typical of DFS. An analysis of the available literature indicates that in diabetic patients the number of EPCs declines and their functioning is impaired. Endothelial progenitor cells are crucial to vasculogenesis and angiogenesis during ischemic neovascularization. The pathomechanisms underlying impaired angiogenesis in patients with DFS is complicated, but the discovery of EPCs has shed new light on the pathogenesis of many diseases, including diabetes foot syndrome.

  15. [Cytokines, endothelial dysfunction, and insulin resistance].

    PubMed

    de Carvalho, Maria Helena C; Colaço, André Luiz; Fortes, Zuleica Bruno

    2006-04-01

    Endothelial dysfunction is associated with several vascular conditions as atherosclerosis, hypertension, hyperlipidemia and diabetes mellitus. In all these conditions insulin resistance (IR) is present. Cytokines are low molecular weight proteins with several endocrine and metabolic functions that participate of inflammation and immune response. Several of these cytokines are independent risk factors for cerebrovascular and coronary artery disease. The major sources of cytokines (adipokines) are the visceral and subcutaneous adipose tissues. Thus, increased adipose tissue mass is associated with alteration in adipokine production as over expression of tumor necrosis factor alpha, interleukin 6, plasminogen activator inhibitor 1, and under expression of adiponectin in adipocite tissue. The pro-inflammatory status associated with these changes provides a potential link between IR and endothelial dysfunction, the early stage in the atherosclerotic process, in obese individuals, and type 2 diabetic patients. Reduction of adipose tissue mass through weight reduction in association with exercise reduces TNF-alpha, IL-6, and PAI-1, increases adiponectin, and is associated with improved insulin sensitivity and endothelial function. This review will focus on the evidence for regulation of endothelial function by insulin and the adypokines such as adyponectin, leptin, resistin, IL-6 and TNF-alpha. Interaction between insulin signaling and adypokines will be discussed, as well as the concept that aberrant adypokine secretion in IR and/or obesity impairs endothelial function and contributes further to reduce insulin sensitivity.

  16. PECAM-1: regulator of endothelial junctional integrity.

    PubMed

    Privratsky, Jamie R; Newman, Peter J

    2014-03-01

    PECAM-1 (also known as CD31) is a cellular adhesion and signaling receptor comprising six extracellular immunoglobulin (Ig)-like homology domains, a short transmembrane domain and a 118 amino acid cytoplasmic domain that becomes serine and tyrosine phosphorylated upon cellular activation. PECAM-1 expression is restricted to blood and vascular cells. In circulating platelets and leukocytes, PECAM-1 functions largely as an inhibitory receptor that, via regulated sequential phosphorylation of its cytoplasmic domain, limits cellular activation responses. PECAM-1 is also highly expressed at endothelial cell intercellular junctions, where it functions as a mechanosensor, as a regulator of leukocyte trafficking and in the maintenance of endothelial cell junctional integrity. In this review, we will describe (1) the functional domains of PECAM-1 and how they contribute to its barrier-enhancing properties, (2) how the physical properties of PECAM-1 influence its subcellular localization and its ability to influence endothelial cell barrier function, (3) various stimuli that initiate PECAM-1 signaling and/or function at the endothelial junction and (4) cross-talk of PECAM-1 with other junctional molecules, which can influence endothelial cell function. PMID:24435645

  17. Endothelial Cell Response to Fusobacterium nucleatum.

    PubMed

    Mendes, Reila Tainá; Nguyen, Daniel; Stephens, Danielle; Pamuk, Ferda; Fernandes, Daniel; Van Dyke, Thomas E; Kantarci, Alpdogan

    2016-07-01

    Vascular response is an essential aspect of an effective immune response to periodontal disease pathogens, as new blood vessel formation contributes to wound healing and inflammation. Gaining a greater understanding of the factors that affect vascular response may then contribute to future breakthroughs in dental medicine. In this study, we have characterized the endothelial cell response to the common bacterium Fusobacterium nucleatum, an important bridging species that facilitates the activity of late colonizers of the dental biofilm. Endothelial cells were infected with Fusobacterium nucleatum (strain 25586) for periods of 4, 12, 24, or 48 h. Cell proliferation and tube formation were analyzed, and expression of adhesion molecules (CD31 and CD34) and vascular endothelial growth factor (VEGF) receptors 1 and 2 was measured by fluorescence-activated cell sorter (FACS) analysis. Data indicate that F. nucleatum impaired endothelial cell proliferation and tube formation. The findings suggest that the modified endothelial cell response acts as a mechanism promoting the pathogenic progression of periodontal diseases and may potentially suggest the involvement of periodontopathogens in systemic diseases associated with periodontal inflammation.

  18. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Engine Repair.

    ERIC Educational Resources Information Center

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory and construction, inspection diagnoses, and service and overhaul of automotive engines. The course is comprised of five units: (1) Fundamentals of Four-Cycle Engines, (2) Engine Construction, (3) Valve Train, (4) Lubricating Systems, and (5)…

  19. Regular Exercise Training Increases the Number of Endothelial Progenitor Cells and Decreases Homocysteine Levels in Healthy Peripheral Blood

    PubMed Central

    Choi, Jeong Kyu; Moon, Ki Myung; Jung, Seok Yun; Kim, Ji Yong; Choi, Sung Hyun; Kim, Da Yeon; Kang, Songhwa; Chu, Chong Woo

    2014-01-01

    Endothelial progenitor cells (EPCs) are known to play an important role in the repair of damaged blood vessels. We used an endothelial progenitor cell colony-forming assay (EPC-CFA) to determine whether EPC numbers could be increased in healthy individuals through regular exercise training. The number of functional EPCs obtained from human peripheral blood-derived AC133 stem cells was measured after a 28-day regular exercise training program. The number of total endothelial progenitor cell colony-forming units (EPC-CFU) was significantly increased compared to that in the control group (p=0.02, n=5). In addition, we observed a significant decrease in homocysteine levels followed by an increase in the number of EPC-CFUs (p=0.04, n=5), indicating that the 28-day regular exercise training could increase the number of EPC colonies and decrease homocysteine levels. Moreover, an inverse correlation was observed between small-endothelial progenitor cell colony-forming units (small-EPC-CFUs) and plasma homocysteine levels in healthy men (r=-0.8125, p=0.047). We found that regular exercise training could increase the number of EPC-CFUs and decrease homocysteine levels, thus decreasing the cardiovascular disease risk in men. PMID:24757379

  20. An experimental investigation on the ultimate strength of epoxy repaired braced partial infilled RC frames

    NASA Astrophysics Data System (ADS)

    Dubey, Shailendra Kumar Damodar; Kute, Sunil

    2014-09-01

    Due to earthquake, buildings are damaged partially or completely. Particularly structures with soft storey are mostly affected. In general, such damaged structures are repaired and reused. In this regard, an experimental investigation was planned and conducted on models of single-bay, single-storey of partial concrete infilled reinforced concrete (RC) frames up to collapse with corner, central and diagonal steel bracings. Such collapsed frames were repaired with epoxy resin and retested. The initiative was to identify the behaviour, extent of restored ultimate strength and deflection of epoxy-retrofitted frames in comparison to the braced RC frames. The performance of such frames has been considered only for lateral loads. In comparison to bare RC frames, epoxy repaired partial infilled frames have significant increase in the lateral load capacity. Central bracing is more effective than corner and diagonal bracing. For the same load, epoxy repaired frames have comparable deflection than similar braced frames.

  1. Influence of XRCC1 Genetic Polymorphisms on Ionizing Radiation-Induced DNA Damage and Repair

    PubMed Central

    Sterpone, Silvia; Cozzi, Renata

    2010-01-01

    It is well known that ionizing radiation (IR) can damage DNA through a direct action, producing single- and double-strand breaks on DNA double helix, as well as an indirect effect by generating oxygen reactive species in the cells. Mammals have evolved several and distinct DNA repair pathways in order to maintain genomic stability and avoid tumour cell transformation. This review reports important data showing a huge interindividual variability on sensitivity to IR and in susceptibility to developing cancer; this variability is principally represented by genetic polymorphisms, that is, DNA repair gene polymorphisms. In particular we have focussed on single nucleotide polymorphisms (SNPs) of XRCC1, a gene that encodes for a scaffold protein involved basically in Base Excision Repair (BER). In this paper we have reported and presented recent studies that show an influence of XRCC1 variants on DNA repair capacity and susceptibility to breast cancer. PMID:20798883

  2. Pericyte abundance affects sucrose permeability in cultures of rat brain microvascular endothelial cells.

    PubMed

    Parkinson, Fiona E; Hacking, Cindy

    2005-07-01

    The blood-brain barrier is a physical and metabolic barrier that restricts diffusion of blood-borne substances into brain. In vitro models of the blood-brain barrier are used to characterize this structure, examine mechanisms of damage and repair and measure permeability of test substances. The core component of in vitro models of the blood-brain barrier is brain microvascular endothelial cells. We cultured rat brain microvascular endothelial cells (RBMEC) from isolated rat cortex microvessels. After 2-14 days in vitro (DIV), immunohistochemistry of these cells showed strong labeling for zona occludens 1 (ZO-1), a tight junction protein expressed in endothelial cells. Pericytes were also present in these cultures, as determined by expression of alpha-actin. The present study was performed to test different cell isolation methods and to compare the resulting cell cultures for abundance of pericytes and for blood-brain barrier function, as assessed by 14C-sucrose flux. Two purification strategies were used. First, microvessels were preabsorbed onto uncoated plastic for 4 h, then unattached microvessels were transferred to coated culture ware. Second, microvessels were incubated with an antibody to platelet-endothelial cell adhesion molecule 1 (PECAM-1; CD31) precoupled to magnetic beads, and a magnetic separation procedure was performed. Our results indicate that immunopurification, but not preadsorption, was an effective method to purify microvessels and reduce pericyte abundance in the resulting cultures. This purification significantly reduced 14C-sucrose fluxes across cell monolayers. These data indicate that pericytes can interfere with the development of blood-brain barrier properties in in vitro models that utilize primary cultures of RBMECs.

  3. Biophysical Properties of Scaffolds Modulate Human Blood Vessel Formation from Circulating Endothelial Colony-Forming Cells

    NASA Astrophysics Data System (ADS)

    Critser, Paul J.; Yoder, Mervin C.

    A functional vascular system forms early in development and is continually remodeled throughout the life of the organism. Impairment to the regeneration or repair of this system leads to tissue ischemia, dysfunction, and disease. The process of vascular formation and remodeling is complex, relying on local microenvironmental cues, cytokine signaling, and multiple cell types to function properly. Tissue engineering strategies have attempted to exploit these mechanisms to develop functional vascular networks for the generation of artificial tissues and therapeutic strategies to restore tissue homeostasis. The success of these strategies requires the isolation of appropriate progenitor cell sources which are straightforward to obtain, display high proliferative potential, and demonstrate an ability to form functional vessels. Several populations are of interest including endothelial colony-forming cells, a subpopulation of endothelial progenitor cells. Additionally, the development of scaffolds to deliver and support progenitor cell survival and function is crucial for the formation of functional vascular networks. The composition and biophysical properties of these scaffolds have been shown to modulate endothelial cell behavior and vessel formation. However, further investigation is needed to better understand how these mechanical properties and biophysical properties impact vessel formation. Additionally, several other cell populations are involved in neoangiogenesis and formation of tissue parenchyma and an understanding of the potential impact of these cell populations on the biophysical properties of scaffolds will also be needed to advance these strategies. This chapter examines how the biophysical properties of matrix scaffolds can influence vessel formation and remodeling and, in particular, the impact on in vivo human endothelial progenitor cell vessel formation.

  4. Smooth muscle progenitor cells from peripheral blood promote the neovascularization of endothelial colony-forming cells

    SciTech Connect

    Joo, Hyung Joon; Seo, Ha-Rim; Jeong, Hyo Eun; Choi, Seung-Cheol; Park, Jae Hyung; Yu, Cheol Woong; Hong, Soon Jun; Chung, Seok; Lim, Do-Sun

    2014-07-11

    Highlights: • Two distinct vascular progenitor cells are induced from adult peripheral blood. • ECFCs induce vascular structures in vitro and in vivo. • SMPCs augment the in vitro and in vivo angiogenic potential of ECFCs. • Both cell types have synergistic therapeutic potential in ischemic hindlimb model. - Abstract: Proangiogenic cell therapy using autologous progenitors is a promising strategy for treating ischemic disease. Considering that neovascularization is a harmonized cellular process that involves both endothelial cells and vascular smooth muscle cells, peripheral blood-originating endothelial colony-forming cells (ECFCs) and smooth muscle progenitor cells (SMPCs), which are similar to mature endothelial cells and vascular smooth muscle cells, could be attractive cellular candidates to achieve therapeutic neovascularization. We successfully induced populations of two different vascular progenitor cells (ECFCs and SMPCs) from adult peripheral blood. Both progenitor cell types expressed endothelial-specific or smooth muscle-specific genes and markers, respectively. In a protein array focused on angiogenic cytokines, SMPCs demonstrated significantly higher expression of bFGF, EGF, TIMP2, ENA78, and TIMP1 compared to ECFCs. Conditioned medium from SMPCs and co-culture with SMPCs revealed that SMPCs promoted cell proliferation, migration, and the in vitro angiogenesis of ECFCs. Finally, co-transplantation of ECFCs and SMPCs induced robust in vivo neovascularization, as well as improved blood perfusion and tissue repair, in a mouse ischemic hindlimb model. Taken together, we have provided the first evidence of a cell therapy strategy for therapeutic neovascularization using two different types of autologous progenitors (ECFCs and SMPCs) derived from adult peripheral blood.

  5. How to Relate Complex DNA Repair Genotypes to Pathway Function and, Ultimately, Health Risk

    SciTech Connect

    Jones, IM

    2002-01-09

    Exposure to ionizing radiation increases the incidence of cancer. However, predicting which individuals are at most risk from radiation exposure is a distant goal. Predictive ability is needed to guide policies that regulate radiation exposure and ensure that medical treatments have maximum benefit and minimum risk. Differences between people in susceptibility to radiation are largely based on their genotype, the genes inherited from their parents. Among the important genes are those that produce proteins that repair DNA damaged by radiation. Base Excision Repair (BER) proteins repair single strand breaks and oxidized bases in DNA. Double Strand Break Repair proteins repair broken chromosomes. Using technologies and information from the Human Genome Project, we have previously determined that the DNA sequence of DNA repair genes varies within the human population. An average of 3-4 different variants were found that affect the protein for each of 37 genes studied. The average frequency of these variants is 5%. Given the many genes in each DNA repair pathway and their many variants, technical ability to determine an individual's repair genotype greatly exceeds ability to interpret the information. A long-term goal is to relate DNA repair genotypes to health risk from radiation. This study focused on the BER pathway. The BER genes are known, variants of the genes have been identified at LLNL, and LLNL had recently developed an assay for BER function using white blood cells. The goal of this initial effort was to begin developing data that could be used to test the hypothesis that many different genotypes have similar DNA repair capacity phenotypes (function). Relationships between genotype and phenotype could then be used to group genotypes with similar function and ultimately test the association of groups of genotypes with health risk from radiation. Genotypes with reduced repair function are expected to increase risk of radiation-induced health effects. The goal

  6. Decreased DNA repair gene expression among individuals exposed to arsenic in United States drinking water.

    PubMed

    Andrew, Angeline S; Karagas, Margaret R; Hamilton, Joshua W

    2003-04-10

    Arsenic is well established as a human carcinogen, but its precise mechanism of action remains unknown. Arsenic does not directly damage DNA, but may act as a carcinogen through inhibition of DNA repair mechanisms, leading indirectly to increased mutations from other DNA damaging agents. The molecular mechanism underlying arsenic inhibition of nucleotide excision repair after UV irradiation (Hartwig et al., Carcinogenesis 1997;18:399-405) is unknown, but could be due to decreased expression of critical genes involved in nucleotide excision repair of damaged DNA. This hypothesis was tested by analyzing expression of repair genes and arsenic exposure in a subset of 16 individuals enrolled in a population based case-control study investigating arsenic exposure and cancer risk in New Hampshire. Toenail arsenic levels were inversely correlated with expression of critical members of the nucleotide excision repair complex, ERCC1 (r(2) = 0.82, p < 0.0001), XPF (r(2) = 0.56, p < 0.002), and XPB (r(2) = 0.75, p < 0.0001). The internal dose marker, toenail arsenic level, was more strongly associated with changes in expression of these genes than drinking water arsenic concentration. Our findings, based on human exposure to arsenic in a US population, show an association between biomarkers of arsenic exposure and expression of DNA repair genes. Although our findings need verification in a larger study group, they are consistent with the hypothesis that inhibition of DNA repair capacity is a potential mechanism for the co-carcinogenic activity of arsenic.

  7. Fetal exposure to a diabetic intrauterine environment resulted in a failure of cord blood endothelial progenitor cell adaptation against chronic hypoxia

    PubMed Central

    Dincer, U Deniz

    2015-01-01

    Gestational diabetes mellitus (GDM) has long-term health consequences, and fetal exposure to a diabetic intrauterine environment increases cardiovascular risk for her adult offspring. Some part of this could be related to their endothelial progenitor cells (EPCs). Understanding the vessel-forming ability of human umbilical cord blood (HUCB)-derived endothelial colony-forming cells (ECFCs) against pathological stress such as GDM response to hypoxia could generate new therapeutic strategies. This study aims to investigate the role of chronic hypoxia in EPCs functional and vessel-forming ability in GDM subjects. Each ECFC was expressed in endothelial and pro-angiogenic specific markers, namely endothelial nitric oxide synthase (eNOS), platelet (PECAM-1) endothelial cell adhesion molecule 1, vascular endothelial-cadherin CdH5 (Ca-dependent cell adhesion molecule), vascular endothelial growth factor A, (VEGFA) and insulin-like growth factor 1 (IGF1). Chronic hypoxia did not affect CdH5, but PECAM1 MRNA expressions were increased in control and GDM subjects. Control hypoxic and GDM normoxic VEGFA MRNA expressions and hypoxia-inducible factor 1-alpha (HIF1α) protein expressions were significantly increased in HUCB ECFCs. GDM resulted in most failure of HUCB ECFC adaptation and eNOS protein expressions against chronic hypoxia. Chronic hypoxia resulted in an overall decline in HUCB ECFCs’ proliferative ability due to reduction of clonogenic capacity and diminished vessel formation. Furthermore, GDM also resulted in most failure of cord blood ECFC adaptation against chronic hypoxic environment. PMID:25565870

  8. Final report [DNA Repair and Mutagenesis - 1999

    SciTech Connect

    Walker, Graham C.

    2001-05-30

    The meeting, titled ''DNA Repair and Mutagenesis: Mechanism, Control, and Biological Consequences'', was designed to bring together the various sub-disciplines that collectively comprise the field of DNA Repair and Mutagenesis. The keynote address was titled ''Mutability Doth Play Her Cruel Sports to Many Men's Decay: Variations on the Theme of Translesion Synthesis.'' Sessions were held on the following themes: Excision repair of DNA damage; Transcription and DNA excision repair; UmuC/DinB/Rev1/Rad30 superfamily of DNA polymerases; Cellular responses to DNA damage, checkpoints, and damage tolerance; Repair of mismatched bases, mutation; Genome-instability, and hypermutation; Repair of strand breaks; Replicational fidelity, and Late-breaking developments; Repair and mutation in challenging environments; and Defects in DNA repair: consequences for human disease and aging.

  9. Redefining endothelial progenitor cells via clonal analysis and hematopoietic stem/progenitor cell principals.

    PubMed

    Yoder, Mervin C; Mead, Laura E; Prater, Daniel; Krier, Theresa R; Mroueh, Karim N; Li, Fang; Krasich, Rachel; Temm, Constance J; Prchal, Josef T; Ingram, David A

    2007-03-01

    The limited vessel-forming capacity of infused endothelial progenitor cells (EPCs) into patients with cardiovascular dysfunction may be related to a misunderstanding of the biologic potential of the cells. EPCs are generally identified by cell surface antigen expression or counting in a commercially available kit that identifies "endothelial cell colony-forming units" (CFU-ECs). However, the origin, proliferative potential, and differentiation capacity of CFU-ECs is controversial. In contrast, other EPCs with blood vessel-forming ability, termed endothelial colony-forming cells (ECFCs), have been isolated from human peripheral blood. We compared the function of CFU-ECs and ECFCs and determined that CFU-ECs are derived from the hematopoietic system using progenitor assays, and analysis of donor cells from polycythemia vera patients harboring a Janus kinase 2 V617F mutation in hematopoietic stem cell clones. Further, CFU-ECs possess myeloid progenitor cell activity, differentiate into phagocytic macrophages, and fail to form perfused vessels in vivo. In contrast, ECFCs are clonally distinct from CFU-ECs, display robust proliferative potential, and form perfused vessels in vivo. Thus, these studies establish that CFU-ECs are not EPCs and the role of these cells in angiogenesis must be re-examined prior to further clinical trials, whereas ECFCs may serve as a potential therapy for vascular regeneration. PMID:17053059

  10. KRIT1 Protein Depletion Modifies Endothelial Cell Behavior via Increased Vascular Endothelial Growth Factor (VEGF) Signaling*

    PubMed Central

    DiStefano, Peter V.; Kuebel, Julia M.; Sarelius, Ingrid H.; Glading, Angela J.

    2014-01-01

    Disruption of endothelial cell-cell contact is a key event in many cardiovascular diseases and a characteristic of pathologically activated vascular endothelium. The CCM (cerebral cavernous malformation) family of proteins (KRIT1 (Krev-interaction trapped 1), PDCD10, and CCM2) are critical regulators of endothelial cell-cell contact and vascular homeostasis. Here we show novel regulation of vascular endothelial growth factor (VEGF) signaling in KRIT1-depleted endothelial cells. Loss of KRIT1 and PDCD10, but not CCM2, increases nuclear β-catenin signaling and up-regulates VEGF-A protein expression. In KRIT1-depleted cells, increased VEGF-A levels led to increased VEGF receptor 2 (VEGFR2) activation and subsequent alteration of cytoskeletal organization, migration, and barrier function and to in vivo endothelial permeability in KRIT1-deficient animals. VEGFR2 activation also increases β-catenin phosphorylation but is only partially responsible for KRIT1 depletion-dependent disruption of cell-cell contacts. Thus, VEGF signaling contributes to modifying endothelial function in KRIT1-deficient cells and microvessel permeability in Krit1+/− mice; however, VEGF signaling is likely not the only contributor to disrupted endothelial cell-cell contacts in the absence of KRIT1. PMID:25320085

  11. Development of Endothelial-Specific Single Inducible Lentiviral Vectors for Genetic Engineering of Endothelial Progenitor Cells.

    PubMed

    Yang, Guanghua; Kramer, M Gabriela; Fernandez-Ruiz, Veronica; Kawa, Milosz P; Huang, Xin; Liu, Zhongmin; Prieto, Jesus; Qian, Cheng

    2015-11-27

    Endothelial progenitor cells (EPC) are able to migrate to tumor vasculature. These cells, if genetically modified, can be used as vehicles to deliver toxic material to, or express anticancer proteins in tumor. To test this hypothesis, we developed several single, endothelial-specific, and doxycycline-inducible self-inactivating (SIN) lentiviral vectors. Two distinct expression cassettes were inserted into a SIN-vector: one controlled by an endothelial lineage-specific, murine vascular endothelial cadherin (mVEcad) promoter for the expression of a transactivator, rtTA2S-M2; and the other driven by an inducible promoter, TREalb, for a firefly luciferase reporter gene. We compared the expression levels of luciferase in different vector constructs, containing either the same or opposite orientation with respect to the vector sequence. The results showed that the vector with these two expression cassettes placed in opposite directions was optimal, characterized by a robust induction of the transgene expression (17.7- to 73-fold) in the presence of doxycycline in several endothelial cell lines, but without leakiness when uninduced. In conclusion, an endothelial lineage-specific single inducible SIN lentiviral vector has been developed. Such a lentiviral vector can be used to endow endothelial progenitor cells with anti-tumor properties.

  12. Apoptosis of Endothelial Cells by 13-HPODE Contributes to Impairment of Endothelial Barrier Integrity

    PubMed Central

    Ryman, Valerie E.; Packiriswamy, Nandakumar

    2016-01-01

    Inflammation is an essential host response during bacterial infections such as bovine mastitis. Endothelial cells are critical for an appropriate inflammatory response and loss of vascular barrier integrity is implicated in the pathogenesis of Streptococcus uberis-induced mastitis. Previous studies suggested that accumulation of linoleic acid (LA) oxygenation products derived from 15-lipoxygenase-1 (15-LOX-1) metabolism could regulate vascular functions. The initial LA derivative from the 15-LOX-1 pathway, 13-hydroperoxyoctadecadienoic acid (HPODE), can induce endothelial death, whereas the reduced hydroxyl product, 13-hydroxyoctadecadienoic acid (HODE), is abundantly produced during vascular activation. However, the relative contribution of specific LA-derived metabolites on impairment of mammary endothelial integrity is unknown. Our hypothesis was that S. uberis-induced LA-derived 15-LOX-1 oxygenation products impair mammary endothelial barrier integrity by apoptosis. Exposure of bovine mammary endothelial cells (BMEC) to S. uberis did not increase 15-LOX-1 LA metabolism. However, S. uberis challenge of bovine monocytes demonstrated that monocytes may be a significant source of both 13-HPODE and 13-HODE during mastitis. Exposure of BMEC to 13-HPODE, but not 13-HODE, significantly reduced endothelial barrier integrity and increased apoptosis. Changing oxidant status by coexposure to an antioxidant during 13-HPODE treatment prevented adverse effects of 13-HPODE, including amelioration of apoptosis. A better understanding of how the oxidant status of the vascular microenvironment impacts endothelial barrier properties could lead to more efficacious treatments for S. uberis mastitis.

  13. Glassy Dynamics, Cell Mechanics and Endothelial Permeability

    PubMed Central

    Hardin, Corey; Rajendran, Kavitha; Manomohan, Greeshma; Tambe, Dhananjay T.; Butler, James P.; Fredberg, Jeffrey J.; Martinelli, Roberta; Carman, Christopher V.; Krishnan, Ramaswamy

    2013-01-01

    A key feature of all inflammatory processes is disruption of the vascular endothelial barrier. Such disruption is initiated in part through active contraction of the cytoskeleton of the endothelial cell (EC). Because contractile forces are propagated from cell to cell across a great many cell-cell junctions, this contractile process is strongly cooperative and highly nonlocal. We show here that the characteristic length scale of propagation is modulated by agonists and antagonists that impact permeability of the endothelial barrier. In the presence of agonists including thrombin, histamine, and H202, force correlation length increases, whereas in the presence of antagonists including sphingosine-1-phosphate, hepatocyte growth factor, and the rho kinase inhibitor, Y27632, force correlation length decreases. Intercellular force chains and force clusters are also evident, both of which are reminiscent of soft glassy materials approaching a glass transition. PMID:23638866

  14. The Effects of Inhaled Nickel Nanoparticles on Murine Endothelial Progenitor Cells

    NASA Astrophysics Data System (ADS)

    Liberda, Eric N.

    Introduction. Particulate air pollution, specifically nickel found on or in particulate matter, has been associated with an increased risk of mortality in human population studies and can cause increases in vascular inflammation, generate reactive oxygen species, alter vasomotor tone, and potentiate atherosclerosis in murine exposures. With the discovery of endothelial progenitor cells (EPCs), a door has been opened which may explain these observed cardiovascular effects associated with inhaled air particles and nickel exposure. In order to further quantify the effects of inhaled nickel nanoparticles and attempt to elucidate how the observed findings from other studies may occur, several whole body inhalation exposure experiments to nickel nanoparticles were performed. Methods. Following whole body exposure to approximately 500mug/m3 of nickel nanoparticles for 5 hrs, bone marrow EPCs from C57BL/6 mice were isolated. EPCs were harvested for their RNA or used in a variety of assays including chemotaxis, tube formation, and proliferation. Gene expression was assessed for important receptors involved in EPC mobilization and homing using RT-PCR methods. EPCs, circulating endothelial progenitor cells, circulating endothelial cells (CECs), and endothelial microparticles (EMPs) were quantified on a BD FACSCalibur to examine endothelial damage and repair associated with the inhalation exposure. Plasma proteins were assessed using the 2D DIGE proteomic approach and commercially available ELISAs. Results and Conclusions. Exposure to inhaled nickel nanoparticles significantly increased both bone marrow EPCs as well as their levels in circulation. CECs were significantly upregulated suggesting that endothelial damage occurred due to the exposure. There was no significant difference in EMPs between the two groups. Tube formation and chemotaxis, but not proliferation, of bone marrow EPCs was impaired in the nickel nanoparticle exposed group. This decrease in EPC function

  15. In vitro and in vivo activation of endothelial cells by colony-stimulating factors.

    PubMed Central

    Bussolino, F; Ziche, M; Wang, J M; Alessi, D; Morbidelli, L; Cremona, O; Bosia, A; Marchisio, P C; Mantovani, A

    1991-01-01

    This study was designed to identify the set of functions activated in cultured endothelial cells by the hematopoietic growth factors, granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage-colony-stimulating factor (GM-CSF), and to compare them with those elicited by prototypic cytokines active on these cells. Moreover, indications as to the in vivo relevance of in vitro effects were obtained. G-CSF and GM-CSF induced endothelial cells to proliferate and migrate. In contrast, unlike appropriate reference cytokines (IL-1 and tumor necrosis factor, IFN-gamma), G-CSF and GM-CSF did not modulate endothelial cell functions related to hemostasis-thrombosis (production of procoagulant activity and of platelet activating factor), inflammation (expression of leukocyte adhesion molecule-1 and production of platelet activating factor), and accessory function (expression of class II antigens of MHC). Other colony-stimulating factors (IL-3 and macrophage-colony-stimulating factor) were inactive on all functions tested. In comparison to basic fibroblast growth factor (bFGF), G-CSF and GM-CSF induced lower maximal proliferation of endothelial cells, whereas migration was of the same order of magnitude. G-CSF and GM-CSF stimulated repair of mechanically wounded endothelial monolayers. Exposure to both cytokines induced shape changes and cytoskeletal reorganization consistent with a migratory phenotype. To explore the in vivo relevance of the in vitro effects of these cytokines on endothelium, we studied the angiogenic activity of human G-CSF in the rabbit cornea. G-CSF, but not the heat-inactivated molecule, had definite angiogenic activity, without any sign of inflammatory reactions. G-CSF was less active than bFGF. However, the combination of a nonangiogenic dose of bFGF with G-CSF resulted in an angiogenic response higher than that elicited by either individual cytokines. Thus, G-CSF and GM-CSF induce endothelial cells to express an activation

  16. Design and physicochemical characterization of poly(amidoamine) nanoparticles and the toxicological evaluation in human endothelial cells: applications to peptide delivery to the brain.

    PubMed

    Coué, Grégory; Freese, Christian; Unger, Ronald E; Kirkpatrick, C James; Pickl, Karin E; Sinner, Frank M; Engbersen, Johan F J

    2013-01-01

    In this study, we investigated nanoparticles formulated by self-assembly of a biodegradable poly(amidoamine) (PAA) and a fluorescently labeled peptide, in their capacity to internalize in endothelial cells and deliver the peptide, with possible applications for brain drug delivery. The nanoparticles were characterized in terms of size, surface charge, and loading efficiency, and were applied on human cerebral microvascular endothelial cells (hCMEC/D3) and human umbilical vein endothelial cells (Huvec) cells. Cell-internalization and cytotoxicity experiments showed that the PAA-based nanocomplexes were essentially nontoxic, and the peptide was successfully internalized into cells. The results indicate that these PAAs have an excellent property as nontoxic carriers for intracellular protein and peptide delivery, and provide opportunities for novel applications in the delivery of peptides to endothelial cells of the brain.

  17. Brain repair and reprogramming: the route to clinical translation.

    PubMed

    Grealish, S; Drouin-Ouellet, J; Parmar, M

    2016-09-01

    The adult brain has a very limited capacity for generation of new neurons, and neurogenesis only takes place in restricted regions. Some evidence for neurogenesis after injury has been reported, but few, if any, neurons are replaced after brain injury or degeneration, and the permanent loss of neurons leads to long-term disability and loss of brain function. For decades, researchers have been developing cell transplantation using exogenous cell sources for brain repair, and this method has now been shown to successfully restore lost function in experimental and clinical trials. Here, we review the development of cell-replacement strategies for brain repair in Parkinson's disease using the example of human foetal brain cells being successfully translated from preclinical findings to clinical trials. These trials demonstrate that cell-replacement therapy is a viable option for patients with Parkinson's disease, but more importantly also show how the limited availability of foetal cells calls for development of novel cell sources and methods for generating new neurons for brain repair. We focus on new stem cell sources that are on the threshold of clinical application for brain repair and discuss emerging cellular reprogramming technologies. Reviewing the current status of direct neural conversion, both in vitro and in vivo, where somatic cells are directly reprogrammed into functional neurons without passing through a stem cell intermediate, we conclude that both methods result in the successful replacement of new neurons that mature and integrate into the host brain. Thus, this new field shows great promise for future brain repair, although much work is still needed in preclinical animal models before it can be seriously considered for clinical applications. PMID:27539906

  18. Cartilage Repair Using Human Embryonic Stem Cell-Derived Chondroprogenitors

    PubMed Central

    Kapacee, Zoher; Peng, Jiang; Lu, Shibi; Lucas, Robert J.; Hardingham, Timothy E.

    2014-01-01

    In initial work, we developed a 14-day culture protocol under potential GMP, chemically defined conditions to generate chondroprogenitors from human embryonic stem cells (hESCs). The present study was undertaken to investigate the cartilage repair capacity of these cells. The chondrogenic protocol was optimized and validated with gene expression profiling. The protocol was also applied successfully to two lines of induced pluripotent stem cells (iPSCs). Chondrogenic cells derived from hESCs were encapsulated in fibrin gel and implanted in osteochondral defects in the patella groove of nude rats, and cartilage repair was evaluated by histomorphology and immunocytochemistry. Genes associated with chondrogenesis were upregulated during the protocol, and pluripotency-related genes were downregulated. Aggregation of chondrogenic cells was accompanied by high expression of SOX9 and strong staining with Safranin O. Culture with PluriSln1 was lethal for hESCs but was tolerated by hESC chondrogenic cells, and no OCT4-positive cells were detected in hESC chondrogenic cells. iPSCs were also shown to generate chondroprogenitors in this protocol. Repaired tissue in the defect area implanted with hESC-derived chondrogenic cells was stained for collagen II with little collagen I, but negligible collagen II was observed in the fibrin-only controls. Viable human cells were detected in the repair tissue at 12 weeks. The results show that chondrogenic cells derived from hESCs, using a chemically defined culture system, when implanted in focal defects were able to promote cartilage repair. This is a first step in evaluating these cells for clinical application for the treatment of cartilage lesions. PMID:25273540

  19. Establishment of outgrowth endothelial cells from peripheral blood.

    PubMed

    Martin-Ramirez, Javier; Hofman, Menno; van den Biggelaar, Maartje; Hebbel, Robert P; Voorberg, Jan

    2012-09-01

    Blood outgrowth endothelial cells (BOECs) are important tools when investigating diagnostic and therapeutic approaches for vascular disease. In this protocol, mononuclear cells are isolated from peripheral blood and plated on type I collagen at ∼135,000 cells per cm(2) in endothelial cell differentiation medium. On average, 0.34 colonies of endothelial cells per milliliter of blood can be obtained. Colonies of endothelial cells become visible after 14-28 d. Upon confluence, these rapidly expanding colonies can be passaged and have been shown to propagate up to 10(18)-fold. Isolated BOECs are phenotypically similar to vascular endothelial cells, as revealed by their cobblestone morphology, the presence of endothelial cell-specific Weibel-Palade bodies and the expression of endothelial cell markers such as VE-cadherin. The protocol presented here also provides a particularly useful tool for the ex vivo assessment of endothelial cell function from patients with different vascular abnormalities. PMID:22918388

  20. 24 CFR 206.47 - Property standards; repair work.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... be repaired in order to ensure that the repaired property will serve as adequate security for the insured mortgage. (b) Assurance that repairs are made. The mortgage may be closed before the repair...