105 results on '"Thrasivoulou C"'
Search Results
2. Impact of photobleaching on quantitative, spatio-temporal, super-resolution imaging of mitochondria in live C. elegans larvae
- Author
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Segos Ioannis, Van Eeckhoven Jens, Greig Alan, Redd Michael, Thrasivoulou Christopher, and Conradt Barbara
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Medical technology ,R855-855.5 ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Super-resolution (SR) 3D rendering allows superior quantitative analysis of intracellular structures but has largely been limited to fixed or ex vivo samples. Here we developed a method to perform SR live imaging of mitochondria during post-embryonic development of C. elegans larvae. Our workflow includes the drug-free mechanical immobilisation of animals using polystyrene nanobeads, which has previously not been used for in vivo SR imaging. Based on the alignment of moving objects and global threshold-based image segmentation, our method enables an efficient 3D reconstruction of individual mitochondria. We demonstrate for the first time that the frequency distribution of fluorescence intensities is not affected by photobleaching, and that global thresholding alone enables the quantitative comparison of mitochondria along timeseries. Our composite approach significantly improves the study of biological structures and processes in SR during C. elegans post-embryonic development. Furthermore, the discovery that image segmentation does not require any prior correction against photobleaching, a fundamental problem in fluorescence microscopy, will impact experimental strategies aimed at quantitatively studying the dynamics of organelles and other intracellular compartments in any biological system.
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- 2024
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3. Tensile strain increased COX-2 expression and PGE2 release leading to weakening of the human amniotic membrane
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Chowdhury, B., David, A.L., Thrasivoulou, C., Becker, D.L., Bader, D.L., and Chowdhury, T.T.
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- 2014
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4. Upregulation of epidermal gap junctional proteins in patients with venous disease
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Kanapathy, M., Simpson, R., Madden, L., Thrasivoulou, C., Mosahebi, A., Becker, D. L., and Richards, T.
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- 2018
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5. Abnormal connexin expression in human chronic wounds
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Sutcliffe, J. E.S., Chin, K. Y., Thrasivoulou, C., Serena, T. E., OʼNeil, S., Hu, R., White, A. M., Madden, L., Richards, T., Phillips, A. R.J., and Becker, D. L.
- Published
- 2015
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6. 1044 Transcriptionally active human papillomavirus (HPV) in male genital lichen sclerosus (MGLSc), penile intraepithelial neoplasia (PeIN), and penile squamous cell carcinoma (PeSCC)
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Kravvas, G., Xie, B., Thrasivoulou, C., Millar, M., Freeman, A., Haider, A., Alnajjar, H., Muneer, A., Lynch, M., and Bunker, C.
- Published
- 2023
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7. Vulnerability to ROS-induced cell death in ageing articular cartilage: The role of antioxidant enzyme activity
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Jallali, N., Ridha, H., Thrasivoulou, C., Underwood, C., Butler, P.E.M., and Cowen, T.
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- 2005
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8. Reactive oxygen species, dietary restriction and neurotrophic factors in age-related loss of myenteric neurons
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Thrasivoulou, C., Soubeyre, V., Ridha, H., Giuliani, D., Giaroni, C., Michael, G. J., Saffrey, M. J., and Cowen, T.
- Published
- 2006
9. Reduced age-related plasticity of neurotrophin receptor expression in selected sympathetic neurons of the rat
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Cowen, T., Woodhoo, A., Sullivan, C. D., Jolly, R., Crutcher, K. A., Wyatt, S., Michael, G. J., Orike, N., Gatzinsky, K., and Thrasivoulou, C.
- Published
- 2003
10. Orbital precession modulates interannual rainfall variability, as recorded in an Early Pleistocene speleothem
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Hopley, Philip J., Weedon, G.P., Brierley, C., Thrasivoulou, C., Herries, A.I.R., Dinckal, A., Richards, D.A., Nita, D.C., Parrish, R.R., Roberts, N.M.W., Sahy, D., and Smith, C.L.
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es - Abstract
Interannual variability of African rainfall impacts local and global communities, but its past behavior and response in future climate projections are poorly understood. This is primarily due to short instrumental records and a lack of long high-resolution palaeoclimate proxy records. Here we present an annually resolved 91,000 year Early Pleistocene record of hydroclimate from the early hominin-bearing Makapansgat Valley, South Africa. Changes in speleothem annual band thickness are dominated by precession over four consecutive orbital cycles with strong millennial-scale periodicity. The frequency of interannual variability (2.0–6.5 yr oscillations) does not change systematically, yet its amplitude is modulated by the orbital forcing. These long-term characteristics of interannual variability are reproduced with transient climate model simulations of water balance for South Africa from the Late Pleistocene to Recent. Based on these results, we suggest that the frequency of interannual variations in southern African rainfall is likely to be stable under anthropogenic warming, but that the size of year-to-year variations may increase. We see an orbitally forced increase in the amplitude of interannual climate variability between 1.8 Ma and 1.7 Ma coincident with the first evidence for the Acheulean stone tool technology.
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- 2018
11. Serum-free culture of dissociated, purified adult and aged sympathetic neurons and quantitative assays of growth and survival
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Orike, N., Thrasivoulou, C., and Cowen, T.
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- 2001
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12. 15 Developmental conditioning with NGF enhances survival in vitro of adult sympathetic neurons
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Campioni-Noack, M, Thrasivoulou, C, and Cowen, T
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Proceedings of the Anatomical Society of Great Britain and Ireland - Published
- 2004
13. Electron Light Microscopy Techniques in Modern Biomedical Microscopy
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Cowen, T. and Thrasivoulou, C.
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Book Reviews - Published
- 1993
14. Differential regulation of survival and growth in adult sympathetic neurons: An in vitro study of neurotrophin responsiveness.
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Orike, N., Thrasivoulou, C., Wrigley, A., and Cowen, T.
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- 2001
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15. Regulation of Rat Sympathetic Nerve Density by Target Tissues and NGF in Maturity and Old Age.
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Thrasivoulou, C. and Cowen, T.
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- 1995
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16. Autoimmunity in ulcerative colitis: tropomyosin is not the major antigenic determinant of the Das monoclonal antibody, 7E12H12.
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Hamilton, M. I., Bradley, N. J., Srai, S. K. S., Thrasivoulou, C., Pounder, R. E., and Wakefield, A. J.
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INFLAMMATORY bowel diseases ,ULCERATIVE colitis ,EPITOPES ,AUTOANTIBODIES ,MONOCLONAL antibodies - Abstract
Ulcerative colitis (UC) has a proposed autoimmune pathogenesis. A 40-kD antigen (P40) has been isolated from UC colon, bound to immunoglobulin. Tropomyosin has been reported as the target antigen of a MoAb (7E12H12) raised against P40. We set out to investigate whether tropomyosin is the major antigenic determinant for 7E12H12. Formalin-fixed, paraffin-processed and cryostat sections of fresh frozen colon from patients with UC. Crohn's disease and normals, were immunostained with 7E12H12 and commercial anti-tropomyosin antibodies. In addition. the immunoreactivity of 7E12H12 with cytoskeletal components was examined on human endothelial cells (HLJVEC) using anti-tropomyosin as a positive control. Con-focal microscopy was used to determine the subcellular localization of signal. An extract of total colonic protein from UC colon was prepared. Using a combination of Western and immunoblotting (dot-blots), the immunoreactivities of both tropomyosin (porcine and chicken) and colon protein extract with either 7E12H12 or commercial anti-tropomyosin were examined. Immunocytochemically. 7E12H12 localized to the apical and basolateral regions of plasma membrane, and to the supranuclear cytoplasm in colonic epithelium. Using anti-tropomyosin antibody it was not possible to identify the cytoskeleton in colonic epithelium. Cytoskeletal components were identifiable in HUVEC cultures with anti-tropomyosin antibody but not with 7EJ2H12. P40 antigen was identified in the colon protein extract by immunoblotting with 7EI2H12. There was clear immunoreactivity between anti-tropomyosin antibody and both chicken and porcine tropomyosin, and the colon protein extract. 7E12H12 did not bind to either chicken or porcine tropomyosin in appropriately controlled systems. We conclude that the pattern of immunostaining with 7E12H12 is not cytoskeletal, and there is no reactivity in immunoblots. between tropomyosin and 7E12H12. Tropomyosin is not the major target antigen of this antibody in ulcerative colitis. [ABSTRACT FROM AUTHOR]
- Published
- 1995
17. Pre-ulcerative villous contraction and microvascular induced by indomethacin in the rat jejunum: a detailed morphological study.
- Author
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ANTHONY, A., DHILLON, A. P., THRASIVOULOU, C., POUNDER, R. E., and WAKEFIELD, A. J.
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- 1995
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18. Assessment of malignant melanoma using non-linear second harmonic generation imaging
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Virich, G., Krenacs, T., Ragoowansi, R., Moir, G., Becker, D., and Thrasivoulou, C.
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- 2007
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19. A microscopical assay using a densitometric application of image analysis to quantify neurotransmitter dynamics
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Cowen, T. and Thrasivoulou, C.
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- 1992
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20. Imaging and analysis of perivascular nerves in human mesenteric and coronary arteries: a comparison between epi-fluorescence and confocal microscopy
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Buwalda, J, Colnot, D.R, Bleys, R.L.A.W, Groen, G.J, Thrasivoulou, C, and Cowen, T
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- 1997
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21. Ulcers produced by ligation of individual gastric mucosal arteries in the guinea pig
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Piasecki, C., Thrasivoulou, C., and Rahim, A.
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- 1989
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22. A cell-based assay for the safety testing of pertussis-containing vaccines
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Greig, Alan J., Markey, K., Thrasivoulou, C., and Fleck, R.
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570 - Abstract
Since the advent of the acellular pertussis vaccine, safety testing has been carried out using the Histamine Sensitisation Assay (HIST assay). This assay is crude in nature and involves large numbers of mice to ensure statistically relevant output. In this work, a permeability assay is described that is a viable alternative to the HIST assay. Human Umbilical Vein Endothelial Cells (HUVECs) in co-culture with peripheral blood mononuclear cells (PBMCs) were used in a permeability assay to distinguish a preparation of DTaP5-IPV-Hib vaccine spiked with pertussis toxin (PTx) from a second control preparation. Using this assay, permeability of the HUVEC monolayer was determined to be a reliable indicator of PTx activity. TNF-α secretion was quantified to determine if there was a correlation with permeability, however, it was highly variable between blood donors. Therefore, it was likely that the permeability was the result of direct interaction between PTx and the HUVECs. Tight junctional (TJ) dysregulation as demonstrated by immunostaining the TJ complex and measuring the transendothelial electrical resistance (TEER) was investigated as the primary cause of PTx-induced permeability. Subsequent investigation into gap junction functionality corroborated this as a reduction in connexin functionality was observed which can be partially explained by TJ dysfunction, however, PTx was also shown to impair connexin 43 deposition at the plasma membrane, demonstrating that TJ expression could be used as alternative and/or combination assay. Additionally, Fluorescence Lifetime Imaging (FLIM) was carried out to directly image PTx activity within the HUVECs, by imaging endogenous NADH fluorescence. PTx activity was shown to be associated with a small increase in protein-bound NADH and since FLIM is non-destructive this allowed other experiments to be carried out on the same generation of HUVECs. In conclusion, the permeability assay described here is capable of detecting PTx in vaccine preparations at concentrations below the required threshold of 4 IU/ml PTx.
- Published
- 2018
23. Cerebrovascular nerves in old rats show reduced accumulation of 5-hydroxytryptamine and loss of nerve fibres
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Cowen, T. and Thrasivoulou, C.
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- 1990
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24. Age-related neurodegeneration is caused by changes in targets and target-derived growth factors, not by intrinsic changes in neurones
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Cowen, T., Gavazzi, I., Andrews, T., and Thrasivoulou, C.
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- 1993
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25. Indomethacin-induced jejunal villous contraction and microvascular occulusion: A detailed morphological study
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Anthony, A, Dhillon, AP, Thrasivoulou, C, Pounder, RE, and Wakefield, AJ
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- 1995
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26. Role of Myofibroblasts in the Repair of Iatrogenic Preterm Membranes Subjected to Mechanical Stimulation.
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Costa E, Thrasivoulou C, Becker DL, Deprest J, David AL, and Chowdhury TT
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- Humans, Female, Pregnancy, Connexin 43 metabolism, Wound Healing physiology, Iatrogenic Disease, Collagen metabolism, Amnion metabolism, Stress, Mechanical, Premature Birth metabolism, Adult, Myofibroblasts metabolism, Fetal Membranes, Premature Rupture metabolism
- Abstract
Objective: We examined the role of myofibroblasts in regulating Cx43 and collagen structure in iatrogenic preterm amniotic membrane (AM) defects subjected to mechanical stimulation., Method: Preterm AM specimens were collected from women undergoing planned preterm caesarean section after in utero intervention for correction of spina bifida by open fetal surgery (n = 4 patients; preterm delivery at 34 + 0 weeks to 35 + 0 weeks). Control specimens taken 5 cm away from the open fetal surgery defect site were compared with wound edge AM. In separate experiments, the effects of mechanical stimulation and co-treatment with Cx43 antisense on matrix and repair proteins were examined. Specimens were immunostained to detect αSMA and Cx43 in myofibroblasts and counterstained with DAPI to quantify nuclei shape. The direction of collagen fibrils in the wound edge region was examined by SHG imaging. Markers for matrix (collagen, elastin, GAG), inflammation (PGE
2 ) and repair (TGFβ1 ) were examined by RT-qPCR and biochemical assays., Results: In iatrogenic preterm AM specimens, the diameter of the open fetal surgery defect ranged between 3.5 and 7.5 cm. At the wound edge of the open fetal surgery defect, αSMA positive myofibroblasts had deformed nuclei and showed abundant Cx43 localized in the cell bodies or formed plaques. In the fibroblast layer, collagen had degenerated in some regions or had polarity near the wound edge. In preterm AM defects, mechanical stimulation and Cx43 antisense increased the levels of collagen and elastin but not GAG or PGE2 release. Mechanical stimulation increased Cx43 and TGFβ1 gene expression., Conclusion: In open fetal surgery defects, myofibroblasts were elongated with collagen fibrils that either degenerated or had polarity. Whilst cells produced substantially higher Cx43 in the fibroblast than in the epithelial layer, they formed plaques, which may prevent migration and delay healing. Mechanical stimulation of preterm AM enhanced matrix repair proteins and the mechanotransduction should be explored to understand how Cx43 contributes to membrane integrity., (© 2024 The Author(s). Prenatal Diagnosis published by John Wiley & Sons Ltd.)- Published
- 2025
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27. Integrating imaging-based classification and transcriptomics for quality assessment of human oocytes according to their reproductive efficiency.
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Viñals Gonzalez X, Thrasivoulou C, Naja RP, Seshadri S, Serhal P, and Gupta SS
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- Humans, Oogenesis genetics, Embryo Implantation, Gene Expression Profiling, Transcriptome genetics, Oocytes
- Abstract
Purpose: Utilising non-invasive imaging parameters to assess human oocyte fertilisation, development and implantation; and their influence on transcriptomic profiles., Methods: A ranking tool was designed using imaging data from 957 metaphase II stage oocytes retrieved from 102 patients undergoing ART. Hoffman modulation contrast microscopy was conducted with an Olympus IX53 microscope. Images were acquired prior to ICSI and processed using ImageJ for optical density and grey-level co-occurrence matrices texture analysis. Single-cell RNA sequencing of twenty-three mature oocytes classified according to their competence was performed., Result(s): Overall fertilisation, blastulation and implantation rates were 73.0%, 62.6% and 50.8%, respectively. Three different algorithms were produced using binary logistic regression methods based on "optimal" quartiles, resulting in an accuracy of prediction of 76.6%, 67% and 80.7% for fertilisation, blastulation and implantation. Optical density, gradient, inverse difference moment (homogeneity) and entropy (structural complexity) were the parameters with highest predictive properties. The ranking tool showed high sensitivity (68.9-90.8%) but with limited specificity (26.5-62.5%) for outcome prediction. Furthermore, five differentially expressed genes were identified when comparing "good" versus "poor" competent oocytes., Conclusion(s): Imaging properties can be used as a tool to assess differences in the ooplasm and predict laboratory and clinical outcomes. Transcriptomic analysis suggested that oocytes with lower competence may have compromised cell cycle either by non-reparable DNA damage or insufficient ooplasmic maturation. Further development of algorithms based on image parameters is encouraged, with an increased balanced cohort and validated prospectively in multicentric studies., (© 2023. The Author(s).)
- Published
- 2023
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28. Cx43 regulates mechanotransduction mechanisms in human preterm amniotic membrane defects.
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Costa E, Thrasivoulou C, Becker DL, Deprest JA, David AL, and Chowdhury TT
- Subjects
- Pregnancy, Infant, Newborn, Humans, Female, Connexin 43, Cesarean Section, Mechanotransduction, Cellular, Amnion, Fetal Membranes, Premature Rupture
- Abstract
Objective: The effects of mechanical stimulation in preterm amniotic membrane (AM) defects were explored., Methods: Preterm AM was collected from women undergoing planned preterm caesarean section (CS) due to fetal growth restriction or emergency CS after spontaneous preterm prelabour rupture of the membranes (sPPROM). AM explants near the cervix or placenta were subjected to trauma and/or mechanical stimulation with the Cx43 antisense. Markers for nuclear morphology (DAPI), myofibroblasts (αSMA), migration (Cx43), inflammation (PGE
2 ) and repair (collagen, elastin and transforming growth factor β [TGFβ1 ]) were examined by confocal microscopy, second harmonic generation, qPCR and biochemical assays., Results: In preterm AM defects, myofibroblast nuclei were highly deformed and contractile and expressed αSMA and Cx43. Mechanical stimulation increased collagen fibre polarisation and the effects on matrix markers were dependent on tissue region, disease state, gestational age and the number of fetuses. PGE2 levels were broadly similar but reduced after co-treatment with Cx43 antisense in late sPPROM AM defects. TGFβ1 and Cx43 gene expression were significantly increased after trauma and mechanical stimulation but this response dependent on gestational age., Conclusion: Mechanical stimulation affects Cx43 signalling and cell/collagen mechanics in preterm AM defects. Establishing how Cx43 regulates mechanosignalling could be an approach to repair tissue integrity after trauma., (© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)- Published
- 2023
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29. Opposite changes in the expression of clathrin and caveolin-1 in normal and cancerous human prostate tissue: putative clathrin-mediated recycling of EGFR.
- Author
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Xie B, Zuhair H, Henrique R, Millar M, Robson T, Thrasivoulou C, Dickens K, Pendjiky J, Muneer A, Patel H, and Ahmed A
- Subjects
- Male, Humans, Clathrin metabolism, Prostate, ErbB Receptors metabolism, Endocytosis, Caveolin 1 metabolism, Prostatic Neoplasms
- Abstract
Endocytosis, an important macromolecule uptake process in cells, is known to be dysregulated in cancer. Clathrin and caveolin-1 proteins play a major role in receptor-mediated endocytosis. We have used a quantitative, unbiased and semi-automated method to measure in situ protein expression of clathrin and caveolin-1 in cancerous and paired normal (cancer adjacent, non-cancerous) human prostate tissue. There was a significant (p < 0.0001) increase in the expression of clathrin in prostate cancer samples (N = 29, n = 91) compared to normal tissue (N = 29, n = 67) (N = number of patients, n = number of cores in tissue arrays). Conversely, there was a significant (p < 0.0001) decrease in expression of caveolin-1 in prostate cancer tissue compared to normal prostate tissue. The opposite change in expression of the two proteins was highly correlated to increasing cancer aggressiveness. There was also a concurrent increase in the expression of epidermal growth factor receptor (EGFR), a key receptor in carcinogenesis, with clathrin in prostate cancer tissue, indicating recycling of EGFR through clathrin-mediated endocytosis (CME). These results indicate that in prostate cancer, caveolin-1-mediated endocytosis (CavME) may be acting as a brake and increase in CME may facilitate tumorigenicity and aggressiveness of prostate cancer through recycling of EGFR. Changes in the expression of these proteins can also potentially be used as a biomarker for prostate cancer to aid in diagnosis and prognosis and clinical decision-making., (© 2023. The Author(s).)
- Published
- 2023
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30. Cx43 mediates changes in myofibroblast contraction and collagen release in human amniotic membrane defects after trauma.
- Author
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Costa E, Okesola BO, Thrasivoulou C, Becker DL, Deprest JA, David AL, and Chowdhury TT
- Subjects
- Extraembryonic Membranes metabolism, Female, Fetal Membranes, Premature Rupture metabolism, Humans, Pregnancy, Vimentin metabolism, Wound Healing physiology, Amnion metabolism, Collagen metabolism, Connexin 43 metabolism, Myofibroblasts metabolism
- Abstract
The wound healing capacity of the fetal membranes after spontaneous or iatrogenic membrane rupture is unclear. We examined the healing mechanisms in amniotic membrane (AM) defects after trauma. Traumatised human AM defects were cultured for 4 days. Markers for nuclear (DAPI), cell type (vimentin, αSMA) and healing (Cx43, TGFβ
1 , collagen) were examined by immunofluorescence (IMF) confocal microscopy, Second Harmonic Generation (SHG) imaging and RT-qPCR. After trauma, AMCs and myofibroblasts migrated to the AM wound edge. Within four days, αSMA expressing myofibroblasts showed abundant Cx43 localized in the cytoplasmic processes. The highly contractile spindle-shaped myofibroblasts were present in the defect site and released collagen. In contrast, AMCs expressed vimentin and formed Cx43 plaques between cells found in the outer edges of the wound. Whilst AMCs were absent in the defect site, αSMA expressing myofibroblasts continued to elongate and polarize the collagen fibres. Both TGFβ1 and Cx43 gene expression were significantly increased after trauma. Cx43 has differential effects on AM cell populations that increase cellularity, contraction and potentially migration to the wound edge resulting in collagen polarisation in the AM defect site. Establishing how Cx43 regulates AM cell function could be an approach to repair defects in the membranes after trauma., (© 2021. The Author(s).)- Published
- 2021
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31. Contractile function of detrusor smooth muscle from children with posterior urethral valves - The role of fibrosis.
- Author
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Johal N, Cao K, Arthurs C, Millar M, Thrasivoulou C, Ahmed A, Jabr RI, Wood D, Cuckow P, and Fry CH
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- Child, Fibrosis, Humans, Muscle Contraction, Muscle, Smooth, Urinary Bladder Diseases
- Abstract
Introduction: Posterior urethral valves (PUV) is the most common cause of congenital bladder outflow obstruction with persistent lower urinary tract and renal morbidities. There is a spectrum of functional bladder disorders ranging from hypertonia to bladder underactivity, but the aetiology of these clinical conditions remains unclear., Aims and Objectives: We tested the hypothesis that replacement of detrusor muscle with non-muscle cells and excessive deposition of connective tissue is an important factor in bladder dysfunction with PUV. We used isolated detrusor samples from children with PUV and undergoing primary or secondary procedures in comparison to age-matched data from children with functionally normal bladders. In vitro contractile properties, as well as passive stiffness, were measured and matched to histological assessment of muscle and connective tissue. We examined if a major pathway for fibrosis was altered in PUV tissue samples., Methods: Isometric contractions were measured in vitro in response to either stimulation of motor nerves to detrusor or exposure to cholinergic and purinergic receptor agonists. Passive mechanical stiffness was measured by rapid stretching of the tissue and recording changes to muscle tension. Histology measured the relative amounts of detrusor muscle and connective tissue. Multiplex quantitative immunofluorescence labelling using five epitope markers was designed to determine cellular pathways, in particular the Wnt-signalling pathway, responsible for any changes to excessive deposition of connective tissue., Results and Discussion: PUV tissue showed equally reduced contractile function to efferent nerve stimulation or exposure to contractile agonists. Passive muscle stiffness was increased in PUV tissue samples. The smooth muscle:connective tissue ratio was also diminished and mirrored the reduction of contractile function and the increase of passive stiffness. Immunofluorescence labelling showed in PUV samples increased expression of the matrix metalloproteinase, MMP-7; as well as cyclin-D1 expression suggesting cellular remodelling. However, elements of a fibrosis pathway associated with Wnt-signalling were either reduced (β-catenin) or unchanged (c-Myc). The accumulation of extracellular matrix, containing collagen, will contribute to the reduced contractile performance of the bladder wall. It will also increase tissue stiffness that in vivo would lead to reduced filling compliance., Conclusions: Replacement of smooth muscle with fibrosis is a major contributory factor in contractile dysfunction in the hypertonic PUV bladder. This suggests that a potential strategy to restore normal contractile and filling properties is development of the effective use of antifibrotic agents., Competing Interests: Conflicts of interest The authors have no conflicts of interest with respect this submission., (Copyright © 2020 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2021
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32. Regulation of the CoA Biosynthetic Complex Assembly in Mammalian Cells.
- Author
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Baković J, López Martínez D, Nikolaou S, Yu BYK, Tossounian MA, Tsuchiya Y, Thrasivoulou C, Filonenko V, and Gout I
- Subjects
- A549 Cells, Coenzyme A biosynthesis, HEK293 Cells, Humans, Insulin metabolism, Intercellular Signaling Peptides and Proteins metabolism, Signal Transduction, Biosynthetic Pathways genetics, Coenzyme A metabolism, Gene Expression Regulation, Oxidative Stress
- Abstract
Coenzyme A (CoA) is an essential cofactor present in all living cells. Under physiological conditions, CoA mainly functions to generate metabolically active CoA thioesters, which are indispensable for cellular metabolism, the regulation of gene expression, and the biosynthesis of neurotransmitters. When cells are exposed to oxidative or metabolic stress, CoA acts as an important cellular antioxidant that protects protein thiols from overoxidation, and this function is mediated by protein CoAlation. CoA and its derivatives are strictly maintained at levels controlled by nutrients, hormones, metabolites, and cellular stresses. Dysregulation of their biosynthesis and homeostasis has deleterious consequences and has been noted in a range of pathological conditions, including cancer, diabetes, Reye's syndrome, cardiac hypertrophy, and neurodegeneration. The biochemistry of CoA biosynthesis, which involves five enzymatic steps, has been extensively studied. However, the existence of a CoA biosynthetic complex and the mode of its regulation in mammalian cells are unknown. In this study, we report the assembly of all five enzymes that drive CoA biosynthesis, in HEK293/Pank1β and A549 cells, using the in situ proximity ligation assay. Furthermore, we show that the association of CoA biosynthetic enzymes is strongly upregulated in response to serum starvation and oxidative stress, whereas insulin and growth factor signaling downregulate their assembly.
- Published
- 2021
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33. Potential sealing and repair of human FM defects after trauma with peptide amphiphiles and Cx43 antisense.
- Author
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Barrett DW, Okesola BO, Costa E, Thrasivoulou C, Becker DL, Mata A, Deprest JA, David AL, and Chowdhury TT
- Subjects
- Adult, Amniotic Fluid chemistry, Coculture Techniques, Drug Evaluation, Preclinical, Extraembryonic Membranes ultrastructure, Female, Fetoscopy adverse effects, Humans, Peptides chemistry, Pregnancy, Antisense Elements (Genetics) administration & dosage, Connexin 43 antagonists & inhibitors, Extraembryonic Membranes injuries, Peptides administration & dosage, Wound Healing drug effects
- Abstract
Objective: We examined whether peptide amphiphiles functionalised with adhesive, migratory or regenerative sequences could be combined with amniotic fluid (AF) to form plugs that repair fetal membrane (FM) defects after trauma and co-culture with connexin 43 (Cx43) antisense., Methods: We assessed interactions between peptide amphiphiles and AF and examined the plugs in FM defects after trauma and co-culture with the Cx43antisense., Results: Confocal microscopy confirmed directed self-assembly of peptide amphiphiles with AF to form a plug within minutes, with good mechanical properties. SEM of the plug revealed a multi-layered, nanofibrous network that sealed the FM defect after trauma. Co-culture of the FM defect with Cx43 antisense and plug increased collagen levels but reduced GAG. Culture of the FM defect with peptide amphiphiles incorporating regenerative sequences for 5 days, increased F-actin and nuclear cell contraction, migration and polarization of collagen fibers across the FM defect when compared to control specimens with minimal repair., Conclusions: Whilst the nanoarchitecture revealed promising conditions to seal iatrogenic FM defects, the peptide amphiphiles need to be designed to maximize repair mechanisms and promote structural compliance with high mechanical tolerance that maintains tissue remodeling with Cx43 antisense for future treatment., (© 2020 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)
- Published
- 2021
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34. Copolymer Composition and Nanoparticle Configuration Enhance in vitro Drug Release Behavior of Poorly Water-soluble Progesterone for Oral Formulations.
- Author
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Zhang Y, Zhang R, Illangakoon UE, Harker AH, Thrasivoulou C, Parhizkar M, Edirisinghe M, and Luo CJ
- Subjects
- Biological Availability, Drug Carriers chemistry, Drug Carriers pharmacokinetics, Drug Compounding methods, Drug Delivery Systems, Drug Liberation, Microscopy, Electron, Scanning, Nanoparticles administration & dosage, Particle Size, Solubility, Spectrophotometry, Ultraviolet, Spectroscopy, Fourier Transform Infrared, Water chemistry, X-Ray Diffraction, Nanoparticles chemistry, Polylactic Acid-Polyglycolic Acid Copolymer chemistry, Progesterone administration & dosage, Progesterone pharmacokinetics
- Abstract
Hypothesis: Developing oral formulations to enable effective release of poorly water-soluble drugs like progesterone is a major challenge in pharmaceutics. Coaxial electrospray can generate drug-loaded nanoparticles of strategic compositions and configurations to enhance physiological dissolution and bioavailability of poorly water-soluble drug progesterone., Experiments: Six formulations comprising nanoparticles encapsulating progesterone in different poly(lactide-co-glycolide) (PLGA) matrix configurations and compositions were fabricated and characterized in terms of morphology, molecular crystallinity, drug encapsulation efficiency and release behavior., Findings: A protocol of fabrication conditions to achieve 100% drug encapsulation efficiency in nanoparticles was developed. Scanning electron microscopy shows smooth and spherical morphology of 472.1±54.8 to 588.0±92.1 nm in diameter. Multiphoton Airyscan super-resolution confocal microscopy revealed core-shell nanoparticle configuration. Fourier transform infrared spectroscopy confirmed presence of PLGA and progesterone in all formulations. Diffractometry indicated amorphous state of the encapsulated drug. UV-vis spectroscopy showed drug release increased with hydrophilic copolymer glycolide ratio while core-shell formulations with progesterone co-dissolved in PLGA core exhibited enhanced release over five hours at 79.9±1.4% and 70.7±3.5% for LA:GA 50:50 and 75:25 in comparison with pure progesterone without polymer matrix in the core at 67.0±1.7% and 57.5±2.8%, respectively. Computational modeling showed good agreement with the experimental drug release behavior in vitro., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Zhang et al.)
- Published
- 2020
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35. Equine penile squamous cell carcinoma: expression of biomarker proteins and EcPV2.
- Author
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Arthurs C, Suarez-Bonnet A, Willis C, Xie B, Machulla N, Mair TS, Cao K, Millar M, Thrasivoulou C, Priestnall SL, and Ahmed A
- Subjects
- Animals, Biomarkers, Tumor metabolism, Carcinoma, Squamous Cell diagnosis, Carcinoma, Squamous Cell virology, Cyclin D1 genetics, Cyclin D1 metabolism, Horses, Male, Matrix Metalloproteinase 7 genetics, Matrix Metalloproteinase 7 metabolism, Papillomaviridae physiology, Papillomavirus Infections diagnosis, Papillomavirus Infections virology, Penile Neoplasms diagnosis, Penile Neoplasms virology, Protein Binding, Proto-Oncogene Proteins c-fos genetics, Proto-Oncogene Proteins c-fos metabolism, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, ROC Curve, Tissue Array Analysis methods, Biomarkers, Tumor genetics, Carcinoma, Squamous Cell genetics, Gene Expression Regulation, Neoplastic, Papillomaviridae isolation & purification, Papillomavirus Infections genetics, Penile Neoplasms genetics
- Abstract
Equine penile squamous cell carcinoma (EpSCC) is a relatively common cutaneous neoplasm with a poor prognosis. In this study, we aimed to determine the protein expression and colocalisation of FRA1, c-Myc, Cyclin D1, and MMP7 in normal (NT), tumour (T), hyperplastic epidermis and/or squamous papilloma (Hyp/Pap), poorly-differentiated (PDSCC), or well-differentiated (WDSCC) EpSCC using a tissue array approach. Further objectives were to correlate protein expression to (i) levels of inflammation, using a convolutional neural network (ii) equine papillomavirus 2 (EcPV2) infection, detected using PCR amplification. We found an increase in expression of FRA1 in EpSCC compared to NT samples. c-Myc expression was higher in Hyp/Pap and WDSCC but not PDSCC whereas MMP7 was reduced in WDSCC compared with NT. There was a significant increase in the global intersection coefficient (GIC) of FRA1 with MMP7, c-Myc, and Cyclin D1 in EpSCC. Conversely, GIC for MMP7 with c-Myc was reduced in EpSCC tissue. Inflammation was positively associated with EcPV2 infection in both NT and EpSCC but not Hyp/Pap. Changes in protein expression could be correlated with EcPV2 for Cyclin D1 and c-Myc. Our results evaluate novel biomarkers of EpSCC and a putative correlation between the expression of biomarkers, EcPV2 infection and inflammation.
- Published
- 2020
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36. Wnts control membrane potential in mammalian cancer cells.
- Author
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Ashmore J, Olsen H, Sørensen N, Thrasivoulou C, and Ahmed A
- Subjects
- Cell Membrane drug effects, Cell Membrane physiology, Humans, MCF-7 Cells, Potassium Channels metabolism, TRPM Cation Channels metabolism, Wnt Proteins metabolism, Wnt Proteins pharmacology, Calcium Signaling, Membrane Potentials, Wnt Signaling Pathway
- Abstract
Key Points: Wnt ligands belonging to both canonical and non-canonical Wnt pathways regulate membrane potential signifying a very early event in the signal transduction. Wnts activate K
+ currents by elevating intracellular Ca2+ and trigger Ca2+ release from intracellular stores. Control of potential by Wnt ligands has significant implications for gene transcription and opens up a novel avenue to interfere with this critical pathway., Abstract: The Wnt signalling network determines gene transcription with free intracellular Ca2+ ( Ca i 2 + ) and β-catenin as major intracellular signal transducers. Despite its critical importance during development and disease, many of the basic mechanisms of Wnt signal activation remain unclear. Here we show by single cell recording and simultaneous Ca i 2 + imaging in mammalian prostate cancer cells that an early step in the signal cascade is direct action on the cell membrane potential. We show that Wnt ligands 5A, 9B and 10B rapidly hyperpolarized the cells by activating K+ current by Ca2+ release from intracellular stores. Medium-throughput multi-well recordings showed responses to Wnts at concentrations of 2 nm. We identify a putative target for early events as a TRPM channel. Wnts thus act as ligands for ion channel activation in mammalian cells and membrane potential is an early indicator of control of transcription., (© 2019 The Authors. The Journal of Physiology © 2019 The Physiological Society.)- Published
- 2019
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37. Wnt signaling regulates cytosolic translocation of connexin 43.
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Hou X, Khan MRA, Turmaine M, Thrasivoulou C, Becker DL, and Ahmed A
- Subjects
- Cell Nucleus metabolism, Cells, Cultured, Gap Junctions genetics, Humans, Male, Wnt Signaling Pathway genetics, beta Catenin genetics, beta Catenin metabolism, Connexin 43 metabolism, Gap Junctions metabolism, Wnt Signaling Pathway physiology
- Abstract
The availability of intracellular, stabilized β-catenin, a transcription factor coactivator, is tightly regulated; β-catenin is translocated into the nucleus in response to Wnt ligand binding to its cell membrane receptors. Here we show that Wnt signal activation in mammalian cells activates intracellular mobilization of connexin 43 (Cx43), which belongs to a gap junction protein family, a new target protein in response to extracellular Wnt signal activation. Transmission electron microscopy showed that the nuclear localization of Cx43 was increased by 8- to 10-fold in Wnt5A- and 9B-treated cells compared with controls; this Wnt-induced increase was negated in the cells where Cx43 and β-catenin were knocked down using shRNA. There was a significant ( P < 0.001) and concomitant depletion of the cell membrane and cytosolic signal of Cx43 in Wnt-treated cells with an increase in the nuclear signal for Cx43; this was more obvious in cells where β-catenin was knocked down using shRNA. Conversely, Cx43 knockdown resulted in increased β-catenin in the nucleus in the absence of Wnt activation. Coimmunoprecipitation of Cx43 and β-catenin proteins with a casein kinase (CKIδ) antibody showed that Cx43 interacts with β-catenin and may form part of the so-called destruction complex. Functionally, Wnt activation increased the rate of wound reepithelization in rat skin in vivo.
- Published
- 2019
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38. Targeting mechanotransduction mechanisms and tissue weakening signals in the human amniotic membrane.
- Author
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Barrett DW, John RK, Thrasivoulou C, Mata A, Deprest JA, Becker DL, David AL, and Chowdhury TT
- Subjects
- Amnion physiology, Cervix Uteri metabolism, Collagen metabolism, Connexin 43 genetics, Connexin 43 metabolism, Dinoprostone metabolism, Elastin metabolism, Female, Gene Expression Regulation, Developmental, Humans, Inflammation metabolism, Matrix Metalloproteinases metabolism, Placenta metabolism, Pregnancy, Proto-Oncogene Proteins c-akt genetics, Proto-Oncogene Proteins c-akt metabolism, Amnion metabolism, Mechanotransduction, Cellular physiology
- Abstract
Mechanical and inflammatory signals in the fetal membrane play an important role in extracellular matrix (ECM) remodelling in order to dictate the timing of birth. We developed a mechanical model that mimics repetitive stretching of the amniotic membrane (AM) isolated from regions over the placenta (PAM) or cervix (CAM) and examined the effect of cyclic tensile strain (CTS) on mediators involved in mechanotransduction (Cx43, AKT), tissue remodelling (GAGs, elastin, collagen) and inflammation (PGE
2 , MMPs). In CAM and PAM specimens, the application of CTS increased GAG synthesis, PGE2 release and MMP activity, with concomitant reduction in collagen and elastin content. Co-stimulation with CTS and pharmacological agents that inhibit either Cx43 or AKT, differentially influenced collagen, GAG and elastin in a tissue-dependent manner. SHG confocal imaging of collagen fibres revealed a reduction in SHG intensity after CTS, with regions of disorganisation dependent on tissue location. CTS increased Cx43 and AKT protein and gene expression and the response could be reversed with either CTS, the Cx43 antisense or AKT inhibitor. We demonstrate that targeting Cx43 and AKT prevents strain-induced ECM damage and promotes tissue remodelling mechanisms in the AM. We speculate that a combination of inflammatory and mechanical factors could perturb typical mechanotransduction processes mediated by Cx43 signalling. Cx43 could therefore be a potential therapeutic target to prevent inflammation and preterm premature rupture of the fetal membranes.- Published
- 2019
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39. Differential Free Intracellular Calcium Release by Class II Antiarrhythmics in Cancer Cell Lines.
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Reyes-Corral M, Sørensen NM, Thrasivoulou C, Dasgupta P, Ashmore JF, and Ahmed A
- Subjects
- Adrenergic beta-Antagonists pharmacology, Humans, Kinetics, MCF-7 Cells, PC-3 Cells, Propranolol pharmacology, Receptors, Adrenergic, beta metabolism, Anti-Arrhythmia Agents pharmacology, Calcium metabolism, Intracellular Space drug effects, Intracellular Space metabolism
- Abstract
Class II antiarrhythmics or β -blockers are antisympathetic nervous system agents that act by blocking β -adrenoceptors. Despite their common clinical use, little is known about the effects of β -blockers on free intracellular calcium (Ca
2+ i ), an important cytosolic second messenger and a key regulator of cell function. We investigated the role of four chemical analogs, commonly prescribed β -blockers (atenolol, metoprolol, propranolol, and sotalol), on Ca2+ i release and whole-cell currents in mammalian cancer cells (PC3 prostate cancer and MCF7 breast cancer cell lines). We discovered that only propranolol activated free Ca2+ i release with distinct kinetics, whereas atenolol, metoprolol, and sotalol did not. The propranolol-induced Ca2+ i release was significantly inhibited by the chelation of extracellular calcium with ethylene glycol tetraacetic acid (EGTA) and by dantrolene, an inhibitor of the endoplasmic reticulum (ER) ryanodine receptor channels, and it was completely abolished by 2-aminoethoxydiphenyl borate, an inhibitor of the ER inositol-1,4,5-trisphosphate (IP3 ) receptor channels. Exhaustion of ER stores with 4-chloro- m -cresol, a ryanodine receptor activator, or thapsigargin, a sarco/ER Ca2+ ATPase inhibitor, precluded the propranolol-induced Ca2+ i release. Finally, preincubation of cells with sotalol or timolol, nonselective blockers of β -adrenoceptors, also reduced the Ca2+ i release activated by propranolol. Our results show that different β -blockers have differential effects on whole-cell currents and free Ca2+ i release and that propranolol activates store-operated Ca2+ i release via a mechanism that involves calcium-induced calcium release and putative downstream transducers such as IP3 The differential action of class II antiarrhythmics on Ca2+ i release may have implications on the pharmacology of these drugs., (Copyright © 2019 by The Author(s).)- Published
- 2019
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40. Three-dimensional cancer cell culture in high-yield multiscale scaffolds by shear spinning.
- Author
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Ahmed AA, Luo CJ, Perez-Garrido S, Browse CR, Thrasivoulou C, Stoyanov SD, Smoukov SK, and Gout I
- Subjects
- Cell Proliferation, Cell Survival, Humans, Microscopy, Fluorescence, Tissue Engineering, Tissue Scaffolds, Tumor Cells, Cultured, Shear Strength
- Abstract
Polymeric scaffolds comprising two size scales of microfibers and submicron fibers can better support three-dimensional (3D) cell growth in tissue engineering, making them an important class of healthcare material. However, a major manufacturing barrier hampers their translation into wider practical use: scalability. Traditional production of two-scale scaffolds by electrospinning is slow and costly. For day-to-day cell cultures, the scaffolds need to be affordable, made in high yield to drive down cost. Combining expertise from academia and industry from the United Kingdom and United States, this study uses a new series of high-yield, low-cost scaffolds made by shear spinning for tissue engineering. The scaffolds comprise interwoven submicron fibers and microfibers throughout as observed under scanning electron microscopy and demonstrate good capability to support cell culturing for tumor modeling. Three model human cancer cell lines (HEK293, A549 and MCF-7) with stable expression of GFP were cultured in the scaffolds and found to exhibit efficient cell attachment and sustained 3D growth and proliferation for 30 days. Cryosection and multiphoton fluorescence microscopy confirmed the formation of compact 3D cell clusters throughout the scaffolds. In addition, comparative growth curves of 2D and 3D cultures show significant cell-type-dependent differences. This work applies high-yield shear-spun scaffolds in mammalian tissue engineering and brings practical, affordable applications of multiscale scaffolds closer to reality. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2750, 2019., (© 2018 American Institute of Chemical Engineers.)
- Published
- 2019
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41. Quantitative Analysis of Seven New Prostate Cancer Biomarkers and the Potential Future of the 'Biomarker Laboratory'.
- Author
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Cao K, Arthurs C, Atta-Ul A, Millar M, Beltran M, Neuhaus J, Horn LC, Henrique R, Ahmed A, and Thrasivoulou C
- Abstract
Prostate cancer is the third highest cause of male mortality in the developed world, with the burden of the disease increasing dramatically with demographic change. There are significant limitations to the current diagnostic regimens and no established effective screening modality. To this end, research has discovered hundreds of potential 'biomarkers' that may one day be of use in screening, diagnosis or prognostication. However, the barriers to bringing biomarkers to clinical evaluation and eventually into clinical usage have yet to be realised. This is an operational challenge that requires some new thinking and development of paradigms to increase the efficiency of the laboratory process and add 'value' to the clinician. Value comes in various forms, whether it be a process that is seamlessly integrated into the hospital laboratory environment or one that can provide additional 'information' for the clinical pathologist in terms of risk profiling. We describe, herein, an efficient and tissue-conserving pipeline that uses Tissue Microarrays in a semi-automated process that could, one day, be integrated into the hospital laboratory domain, using seven putative prostate cancer biomarkers for illustration.
- Published
- 2018
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42. Posterior Vitreous Detachment and the Posterior Hyaloid Membrane.
- Author
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Fincham GS, James S, Spickett C, Hollingshead M, Thrasivoulou C, Poulson AV, McNinch A, Richards A, Snead D, Limb GA, and Snead MP
- Subjects
- Adult, Aged, Aged, 80 and over, Basement Membrane chemistry, Female, Humans, Imaging, Three-Dimensional, Immunohistochemistry, Male, Microscopy, Acoustic, Microscopy, Confocal, Middle Aged, Prospective Studies, Vitrectomy, Vitreous Body surgery, Vitreous Detachment surgery, Basement Membrane diagnostic imaging, Collagen metabolism, Vitreous Body pathology, Vitreous Detachment diagnosis
- Abstract
Purpose: Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise anatomic definition. We investigated the morphologic appearance and molecular composition of the posterior hyaloid membrane to determine whether the structure clinically observed enveloping the posterior vitreous surface after posterior vitreous detachment is a true basement membrane and to postulate its origin. Understanding the relationship between the vitreous (in both its attached and detached state) and the internal limiting membrane of the retina is essential to understanding the cause of rhegmatogenous retinal detachment and vitreoretinal interface disorders, as well as potential future prophylactic and treatment strategies., Design: Clinicohistologic correlation study., Participants: Thirty-six human donor globes., Methods: Vitreous bodies identified to have posterior vitreous detachment were examined with phase-contrast microscopy and confocal microscopy after immunohistochemically staining for collagen IV basement membrane markers, in addition to extracellular proteins that characterize the vitreoretinal junction (fibronectin, laminin) and vitreous gel (opticin) markers. The posterior retina similarly was stained to evaluate the internal limiting membrane. Findings were correlated to the clinical appearance of the posterior hyaloid membrane observed during slit-lamp biomicroscopy after posterior vitreous detachment and compared with previously published studies., Main Outcome Measures: Morphologic appearance and molecular composition of the posterior hyaloid membrane., Results: Phase-contrast microscopy consistently identified a creased and distinct glassy membranous sheet enveloping the posterior vitreous surface, correlating closely with the posterior hyaloid membrane observed during slit-lamp biomicroscopy in patients with posterior vitreous detachment. Immunofluorescent confocal micrographs demonstrated the enveloping membranous structure identified on phase-contrast microscopy to show positive stain results for type IV collagen. Immunofluorescence of the residual intact internal limiting membrane on the retinal surface also showed positive stain results for type IV collagen., Conclusions: The results of this study provide immunohistochemical evidence that the posterior hyaloid membrane is a true basement membrane enveloping the posterior hyaloid surface. Because this membranous structure is observed only after posterior vitreous detachment, the results of this study indicate that it forms part of the internal limiting membrane when the vitreous is in its attached state., (Copyright © 2017 American Academy of Ophthalmology. All rights reserved.)
- Published
- 2018
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43. Changes in the extracellular matrix surrounding human chronic wounds revealed by 2-photon imaging.
- Author
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Sutcliffe JES, Thrasivoulou C, Serena TE, Madden L, Richards T, Phillips ARJ, and Becker DL
- Subjects
- Aged, Aged, 80 and over, Chronic Disease, Humans, Male, Middle Aged, Wounds and Injuries physiopathology, Dermis diagnostic imaging, Diabetic Foot diagnostic imaging, Elasticity Imaging Techniques methods, Extracellular Matrix ultrastructure, Varicose Ulcer diagnostic imaging, Wound Healing physiology, Wounds and Injuries diagnostic imaging
- Abstract
Chronic wounds are a growing problem worldwide with no effective therapeutic treatments available. Our objective was to understand the composition of the dermal tissue surrounding venous leg ulcers and diabetic foot ulcers (DFU). We used novel 2-photon imaging techniques alongside classical histology to examine biopsies from the edges of two common types of chronic wound, venous leg ulcers and DFU. Compared to normal intact skin, we found that collagen levels are significantly reduced throughout the dermis of venous leg ulcer biopsies and DFU, with a reduction in both fibril thickness and abundance. Both wound types showed a significant reduction in elastin in the upper dermis, but in DFU, the loss was throughout the dermis. Loss of extracellular matrix correlated with high levels of CD68- and CD18-positive leukocytes. 2-photon imaging of the extracellular matrix in the intact tissue surrounding a chronic wound with a hand-held device may provide a useful clinical indicator on the healing progression or deterioration of these wounds., (© 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)
- Published
- 2017
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44. Expression of ribosomal proteins in normal and cancerous human prostate tissue.
- Author
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Arthurs C, Murtaza BN, Thomson C, Dickens K, Henrique R, Patel HRH, Beltran M, Millar M, Thrasivoulou C, and Ahmed A
- Subjects
- Aged, Biomarkers, Tumor metabolism, Fluorescent Antibody Technique, Humans, Image Interpretation, Computer-Assisted, Male, Middle Aged, Neoplasm Staging, Prostate metabolism, Prostate pathology, Prostatic Neoplasms genetics, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology, ROC Curve, Retrospective Studies, Ribosomal Proteins metabolism, Ribosomes genetics, Ribosomes metabolism, Ribosomes pathology, Tissue Array Analysis, Biomarkers, Tumor genetics, Gene Expression Regulation, Neoplastic, Prostatic Neoplasms diagnosis, Ribosomal Proteins genetics
- Abstract
Few quantifiable tissue biomarkers for the diagnosis and prognosis of prostate cancer exist. Using an unbiased, quantitative approach, this study evaluates the potential of three proteins of the 40S ribosomal protein complex as putative biomarkers of malignancy in prostate cancer. Prostate tissue arrays, constructed from 82 patient samples (245 tissue cores, stage pT3a or pT3b), were stained for antibodies against three ribosomal proteins, RPS19, RPS21 and RPS24. Semi-automated Ox-DAB signal quantification using ImageJ software revealed a significant change in expression of RPS19, RPS21 and RPS24 in malignant vs non-malignant tissue (p<0.0001). Receiver operating characteristics curves were calculated to evaluate the potential of each protein as a biomarker of malignancy in prostate cancer. Positive likelihood ratios for RPS19, RPS21 and RPS24 were calculated as 2.99, 4.21, and 2.56 respectively, indicating that the overexpression of the protein is correlated with the presence of disease. Triple-labelled, quantitative, immunofluorescence (with RPS19, RPS21 and RPS24) showed significant changes (p<0.01) in the global intersection coefficient, a measure of how often two fluorophore signals intersect, for RPS19 and RPS24 only. No change was observed in the co-localization of any other permutations of the three proteins. Our results show that RPS19, RPS21 or RPS24 are upregulated in malignant tissue and may serve as putative biomarkers for prostate cancer.
- Published
- 2017
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45. Trauma induces overexpression of Cx43 in human fetal membrane defects.
- Author
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Barrett DW, Kethees A, Thrasivoulou C, Mata A, Virasami A, Sebire NJ, Engels AC, Deprest JA, Becker DL, David AL, and Chowdhury TT
- Subjects
- Amnion chemistry, Amnion pathology, Cell Survival, Collagen chemistry, Collagen ultrastructure, Epithelial Cells chemistry, Extraembryonic Membranes pathology, Female, Fetal Membranes, Premature Rupture pathology, Fluorescent Antibody Technique, Humans, Mesenchymal Stem Cells chemistry, Microscopy, Confocal, Pregnancy, Wounds and Injuries metabolism, Connexin 43 analysis, Extraembryonic Membranes injuries
- Abstract
Objective: We developed an in vitro model to examine whether trauma induces connexin 43 (Cx43) expression and collagen organisation in the amniotic membrane (AM) of fetal membrane (FM) defects., Method: Term human FM was traumatised in vitro. Cell morphology and Cx43 were examined in the wound edge AM by immunofluorescence (IMF) confocal microscopy and compared to control AM. Collagen microstructure was examined by second harmonic generation (SHG) imaging. Cell viability was assessed with calcein and ethidium staining., Results: After trauma, the AM showed a dense region of cells, which had migrated towards the wound edge. In wound edge AM, Cx43 puncta was preferentially distributed in mesenchymal cells compared to epithelial cells with significant expression in the fibroblast layer than epithelial layer (p < 0.001). In the fibroblast layer, the collagen fibres were highly polarised and aligned in parallel to the axis of the wound edge AM. There was an absence of cell migration across the defect with no healing after 168 h. Cell viability of the FM after trauma was maintained during culture., Conclusion: Cx43 overexpression in wounded AM drives structural changes in collagen that slows down efficacy of cell migration across the FM defect. © 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd., (© 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.)
- Published
- 2017
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46. Intracellular Calcium Mobilization in Response to Ion Channel Regulators via a Calcium-Induced Calcium Release Mechanism.
- Author
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Petrou T, Olsen HL, Thrasivoulou C, Masters JR, Ashmore JF, and Ahmed A
- Subjects
- Cell Line, Tumor, Electrophysiological Phenomena drug effects, Extracellular Space drug effects, Extracellular Space metabolism, Humans, Kinetics, Calcium metabolism, Intracellular Space drug effects, Intracellular Space metabolism, Ion Channels metabolism
- Abstract
Free intracellular calcium ([Ca
2+ ]i ), in addition to being an important second messenger, is a key regulator of many cellular processes including cell membrane potential, proliferation, and apoptosis. In many cases, the mobilization of [Ca2+ ]i is controlled by intracellular store activation and calcium influx. We have investigated the effect of several ion channel modulators, which have been used to treat a range of human diseases, on [Ca2+ ]i release, by ratiometric calcium imaging. We show that six such modulators [amiodarone (Ami), dofetilide, furosemide (Fur), minoxidil (Min), loxapine (Lox), and Nicorandil] initiate release of [Ca2+ ]i in prostate and breast cancer cell lines, PC3 and MCF7, respectively. Whole-cell currents in PC3 cells were inhibited by the compounds tested in patch-clamp experiments in a concentration-dependent manner. In all cases [Ca2+ ]i was increased by modulator concentrations comparable to those used clinically. The increase in [Ca2+ ]i in response to Ami, Fur, Lox, and Min was reduced significantly (P < 0.01) when the external calcium was reduced to nM concentration by chelation with EGTA. The data suggest that many ion channel regulators mobilize [Ca2+ ]i We suggest a mechanism whereby calcium-induced calcium release is implicated; such a mechanism may be important for understanding the action of these compounds., (Copyright © 2017 by The Author(s).)- Published
- 2017
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47. Connexin 43 is overexpressed in human fetal membrane defects after fetoscopic surgery.
- Author
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Barrett DW, David AL, Thrasivoulou C, Mata A, Becker DL, Engels AC, Deprest JA, and Chowdhury TT
- Subjects
- Adult, Amnion injuries, Amnion ultrastructure, Case-Control Studies, Connexin 43 metabolism, Cyclooxygenase 2 metabolism, Extracellular Matrix, Female, Fetofetal Transfusion surgery, Fibril-Associated Collagens, Fluorescent Antibody Technique, Gestational Age, Hernias, Diaphragmatic, Congenital surgery, Humans, Microscopy, Electron, Scanning, Pregnancy, Real-Time Polymerase Chain Reaction, Wound Healing, Young Adult, Amnion metabolism, Connexin 43 genetics, Cyclooxygenase 2 genetics, Fetoscopy, RNA, Messenger metabolism
- Abstract
Objective: We examined whether surgically induced membrane defects elevate connexin 43 (Cx43) expression in the wound edge of the amniotic membrane (AM) and drives structural changes in collagen that affects healing after fetoscopic surgery., Method: Cell morphology and collagen microstructure was investigated by scanning electron microscopy and second harmonic generation in fetal membranes taken from women who underwent fetal surgery. Immunofluoresence and real-time quantitative polymerase chain reaction was used to examine Cx43 expression in control and wound edge AM., Results: Scanning electron microscopy showed dense, helical patterns of collagen fibrils in the wound edge of the fetal membrane. This arrangement changed in the fibroblast layer with evidence of collagen fibrils that were highly polarised along the wound edge but not in control membranes. Cx43 was increased by 112.9% in wound edge AM compared with controls (p < 0.001), with preferential distribution in the fibroblast layer compared with the epithelial layer (p < 0.01). In wound edge AM, mesenchymal cells had a flattened morphology, and there was evidence of poor epithelial migration across the defect. Cx43 and COX-2 expression was significantly increased in wound edge AM compared with controls (p < 0.001)., Conclusion: Overexpression of Cx43 in the AM after fetal surgery induces morphological and structural changes in the collagenous matrix that may interfere with normal healing mechanisms. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd., (© 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.)
- Published
- 2016
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48. The effects of short-term JNK inhibition on the survival and growth of aged sympathetic neurons.
- Author
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Guha I, Slamova I, Chun S, Clegg A, Golos M, Thrasivoulou C, Simons JP, and Al-Shawi R
- Subjects
- Animals, Cell Death genetics, Cell Death physiology, Cells, Cultured, Male, Mice, Inbred C57BL, Molecular Targeted Therapy, Neoplasm Proteins physiology, Nerve Growth Factor physiology, Nerve Growth Factor toxicity, Neurites physiology, Neurodegenerative Diseases genetics, Neurodegenerative Diseases therapy, Protein Precursors toxicity, Rats, Sprague-Dawley, Aging genetics, Aging pathology, Cell Growth Processes genetics, Cell Survival genetics, JNK Mitogen-Activated Protein Kinases antagonists & inhibitors, JNK Mitogen-Activated Protein Kinases physiology, Neurons cytology, Neurons physiology, Sympathetic Nervous System cytology
- Abstract
During the course of normal aging, certain populations of nerve growth factor (NGF)-responsive neurons become selectively vulnerable to cell death. Studies using dissociated neurons isolated from neonates have shown that c-Jun N-terminal kinases (JNKs) are important in regulating the survival and neurite outgrowth of NGF-responsive sympathetic neurons. Unlike neonatal neurons, adult sympathetic neurons are not dependent on NGF for their survival. Moreover, the NGF precursor, proNGF, is neurotoxic for aging but not young adult NGF-responsive neurons. Because of these age-related differences, the effects of JNK inhibition on the survival and growth of sympathetic neurons isolated from aged mice were studied. Aged neurons, as well as glia, were found to be dependent on JNK for their growth but not their survival. Conversely, proNGF neurotoxicity was JNK-dependent and mediated by the p75-interacting protein NRAGE, whereas neurite outgrowth was independent of NRAGE. These results have implications for the potential use of JNK inhibitors as therapies for ameliorating age-related neurodegenerative disease., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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49. Quantitative Expression and Co-Localization of Wnt Signalling Related Proteins in Feline Squamous Cell Carcinoma.
- Author
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Giuliano A, Swift R, Arthurs C, Marote G, Abramo F, McKay J, Thomson C, Beltran M, Millar M, Priestnall S, Dobson J, Costantino-Casas F, Petrou T, McGonnell IM, Davies AJ, Weetman M, Garden OA, Masters JR, Thrasivoulou C, and Ahmed A
- Subjects
- Animals, Carcinoma, Squamous Cell veterinary, Cats, Cyclin D1 metabolism, Hydrogen-Ion Concentration, Matrix Metalloproteinase 7 metabolism, Microtubule-Associated Proteins metabolism, Neoplasm Proteins genetics, Proto-Oncogene Proteins c-myc metabolism, ROC Curve, Transcription Factors metabolism, Wnt Proteins metabolism, beta Catenin metabolism, Carcinoma, Squamous Cell metabolism, Cat Diseases metabolism, Gene Expression Regulation, Neoplastic, Mouth Neoplasms metabolism, Wnt Signaling Pathway
- Abstract
Feline oral squamous cell carcinoma (FOSCC) is an aggressive neoplasm in cats. Little is known about the possible molecular mechanisms that may be involved in the initiation, maintenance and progression of FOSCC. Wnt signalling is critical in development and disease, including many mammalian cancers. In this study, we have investigated the expression of Wnt signalling related proteins using quantitative immunohistochemical techniques on tissue arrays. We constructed tissue arrays with 58 individual replicate tissue samples. We tested for the expression of four key Wnt/ß-catenin transcription targets, namely Cyclin D1 (CCND1 or CD1), FRA1, c-Myc and MMP7. All antibodies showed cross reactivity in feline tissue except MMP7. Quantitative immunohistochemical analysis of single proteins (expressed as area fraction / amount of tissue for normal vs tumor, mean ± SE) showed that the expression of CD1 (3.9 ± 0.5 vs 12.2 ± 0.9), FRA1 (5.5 ± 0.6 vs 16.8 ± 1.1) and c-Myc (5.4 ± 0.5 vs 12.5 ± 0.9) was increased in FOSCC tissue by 2.3 to 3 fold compared to normal controls (p<0.0001). By using a multilabel, quantitative fluorophore technique we further investigated if the co-localization of these proteins (all transcription factors) with each other and in the nucleus (stained with 4',6-diamidino-2-phenylindole, DAPI) was altered in FOSCC compared to normal tissue. The global intersection coefficients, a measure of the proximity of two fluorophore labeled entities, showed that there was a significant change (p < 0.01) in the co-localization for all permutations (e.g. CD1/FRA1 etc), except for the nuclear localization of CD1. Our results show that putative targets of Wnt signalling transcription are up-regulated in FOSCC with alterations in the co-localization of these proteins and could serve as a useful marker for the disease., Competing Interests: Competing Interests: The authors of this manuscript have the following competing interests: AA (principal inventor) and CT and JRM (co-inventors) have filed for a patent through UCL Business for targeting Wnt signaling pathway for ß-catenin related disorders (New British Patent Application no. 1318659.8). AA is an associate editor of PLOS ONE. This do not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials. One co-author (Jenny McKay) works for a commercial organization called IDEXX; another co-author (Malcolm Weetman) works for a commercial organization Independent Vetcare. The corresponding author declares, categorically, that none of the issues stated in these statements alter the authors' adherence to all policies of PLOS ONE.
- Published
- 2016
- Full Text
- View/download PDF
50. Sustained Release of Cx43 Antisense Oligodeoxynucleotides from Coated Collagen Scaffolds Promotes Wound Healing.
- Author
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Gilmartin DJ, Soon A, Thrasivoulou C, Phillips AR, Jayasinghe SN, and Becker DL
- Subjects
- Animals, Delayed-Action Preparations chemistry, Delayed-Action Preparations pharmacokinetics, Delayed-Action Preparations pharmacology, Hydrogels chemistry, Hydrogels pharmacokinetics, Hydrogels pharmacology, Poloxamer chemistry, Poloxamer pharmacokinetics, Poloxamer pharmacology, Rats, Rats, Sprague-Dawley, Wounds and Injuries metabolism, Wounds and Injuries pathology, Coated Materials, Biocompatible chemistry, Collagen chemistry, Connexin 43, Oligodeoxyribonucleotides, Antisense chemistry, Oligodeoxyribonucleotides, Antisense pharmacokinetics, Oligodeoxyribonucleotides, Antisense pharmacology, Tissue Scaffolds chemistry, Wound Healing drug effects, Wounds and Injuries therapy
- Abstract
Antisense oligodeoxynucleotides targeting the mRNA of the gap junction protein Cx43 promote tissue repair in a variety of different wounds. Delivery of the antisense drug has most often been achieved by a thermoreversible hydrogel, Pluronic F-127, which is very effective in the short term but does not allow for sustained delivery over several days. For chronic wounds that take a long time to heal, repeated dosing with the drug may be desirable but is not always compatible with conventional treatments such as the weekly changing of compression bandages on venous leg ulcers. Here the coating of collagen scaffolds with antisense oligonucleotides is investigated and a way to provide protection of the oligodeoxynucleotide drug is found in conjunction with sustained release over a 7 d period. This approach significantly reduces the normal foreign body reaction to the scaffold, which induces an increase of Cx43 protein and an inhibition of healing. As a result of the antisense integration into the scaffold, inflammation is reduced with the rate of wound healing and contracture is significantly improved. This coated scaffold approach may be very useful for treating venous leg ulcers and also for providing a sustained release of any other types of oligonucleotide drugs that are being developed., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
- Full Text
- View/download PDF
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