Andreas Syggros Hospital 5, Ionos Dragoumi st. 16121, Athens Greece
katkypreou@yahoo.com
Position Title: Research Biologist Institute : Nosokomeio Syggrou, Photobiology Labarotory
Brunel University, Uxbridge Middlesex, United Kindgom B.Sc. 1995 - 1998 Medical Biochemistry
Department of Biology, EKEFE Demokritos , Athens PhD 1999-2004 Biochemistry (Fellowship from EKEFE Demokritos) Institute of Basic Research, Histology Lab, in the Biomedical Research Foundation of the Academy of Athens Post-Doctoral 2004-2008 Biochemistry- Molecular Biology
Positions and Employment 2004- 2008: Post-doctoral Researcher, Biomedical Research Foundation of the Academy of Athens 2007 - up today: Research Biologist, Nosokomeio Syggrou – Photbiology Lab
Announcements in international conferences • Sourlingas, T.G., Kypreou, K.P., Kovaiou, O., K.E. Sekeri – Pataryas. HISTONES: APOPTOSIS AND AGEING 3rd International Conference on Basic Biology and Clinical Impact of Immunosenescence, Palermo, April 2002 • Sourlingas, T.G., Doenecke, D., Happel, N., Albig, W., Kypreou, K.P., Tsapali, D.S. and K.E. Sekeri. Changes in the H1 linker histone constitution of chromatin in peripheral blood lymphocytes as function donor age. Immunology and Ageing in Europe (ImAginE). Fourth International Conference on Basic Biology and Clinical Impact of Immunosenescence, Crete, 2003. • Sourlingas, T.G., Kypreou, K.P., Tsapali, D.S. and K.E. Sekeri. An introduction to the role of histones in chromatin remodelling during ageing. Immunology and Ageing in Europe (ImAginE). Fourth International Conference on Basic Biology and Clinical Impact of Immunosenescence, Crete, 2003. • Kypreou, K.P., Sourlingas, T.G., and K.E. Sekeri-Pataryas. The role of histone H1o and histone H4 acetylation during senescence and apoptosis of T lymphocytes. 25th Panhellenic Society for Biological Sciences, Mytilini, 2003. • Tsapali, D.S., Sourlingas, T.G., Kypreou, K.P. and K.E. Sekeri-Pataryas. Regulation of histone H1o expression by retinoic acid and histone deacetylase inhibitors. 25th Panhellenic Society for Biological Sciences, Mytilini, 2003. • Sourlingas, T.G., Kypreou, K.P. Doenecke, D., Happel, N., Albig, W., and K.E. Sekeri. Analysis of the H1 linker histone subtype pattern in peripheral blood lymphocytes as a function of donor age. Hellenic Society for Biochemistry and Molecular Biology. Athens, 2003. • Kypreou K.P., Sekeri-Pataryas K.E. and T.G. Sourlingas. Linker histones and apoptosis. European Cell Death Organization (ECDO), 12th Euroconference on Apoptosis. Chania, Crete, 2004. • Ninios, I. P., Kypreou, K.P., Salpea, P., Sekeri-Pataryas, K.E. and T.G. Sourlingas. Comparative study of the acetylation of histone H4 and histone H1o expression in human leukemic cell lines. 27th Panhellenic Society for Biological Sciences, Nauplio, 2005. • K.P. Kypreou, P. Karamessinis, M. Peroulis, A. Alberti, A.S. Charonis Differential expression of calreticulin during renal fibrosis. 58th Panhellenic Society for Biochemistry and Molecular Biology, Patra 2006. • K.P. Kypreou, P. Karamessinis, M. Peroulis, P. Kavadas, E. Protopapadaki, A. Alberti, A.S. Charonis. Differential expression of carleticulin during renal fibrosis. 9th Annual Meeting of the Hellenic Research Club for Connective Tissue and Matrix Biology. Athens 2007. • Avra A. Alberti, Panagiotis Karamessinis, Michalis Peroulis, Katerina P. Kypreou, Pangiotis P. Politis, Aristidis S. Charonis. Proteomic analysis revealed decreased expression of Erp46 in pancreatic beta cells under exposure to high glucose. 59th Panhellenic Society for Biochemistry and Molecular Biology, Athens 2007. • K.P. Kypreou, Panagiotis Kavadas, P. Karamessinis, M. Peroulis, A. Alberti, Anna Agapaki, Paschalis Sideras, Stelios Psarras, Yasemie Capetanaki, Panagiotis K. Politis, A.S. Charonis. Altered expression of calreticulin during the development of fibrosis. 59th Panhellenic Society for Biochemistry and Molecular Biology, Athens 2007. • K.P. Kypreou, P. Karamessinis, M. Peroulis, A. Alberti, A.S. Charonis. Differential expression of calreticulin during renal fibrosis. 8th International conference of Medical Chemistry , Drug Discovery and Design, Patra 2007. • K.P. Kypreou, P. Karamessinis, M. Peroulis, P. Kavadas, E. Protopapadaki, A. Alberti, A.S. Charonis. Differential expression of carleticulin during renal fibrosis. 19th Meeting of European Renal Cell Study Group, Paris, France 2007. • K.P. Kypreou, P. Kavadas, P. Karamessinis, M. Peroulis, P. Kavadas, A. Alberti, E. Protopapadaki, P. Sideras, Y. Capetanaki, S. Psarras, A.S. Charonis. Role of carleticulin in human fibrosis. 2nd Meeting of the Hellenic Proteomic Society, Kolymbari, 2007.
Abstract: Pulmonary fibrosis is a common feature of a large group of lung diseases. The molecular mechanisms underlying pulmonary fibrosis and the key macromolecules involved are not fully understood yet. In an effort to better understand aspects of pulmonary fibrosis, the established bleomycin injection model in mice was used and the focus of the present study was on integrin-linked kinase (ILK) expression. ILK is an intracellular protein involved in the regulation of integrin-mediated processes. In fibrosis, ILK has been examined in the kidney and in the liver where it mediates epithelial to mesenchymal transition (EMT) and hepatic stellate cell activation, respectively. However, information on ILK's involvement in lung fibrosis is missing. In order to examine ILK's role in pulmonary fibrosis, we used both an in vivo and an in vitro approach. In vivo, the bleomycin model was used in order to examine ILK's expression and localization in the fibrotic lung. In vitro, transforming growth factor-β1 was used to induce fibrotic characteristics and EMT in alveolar epithelial cells. ILK's role in alveolar EMT was studied by siRNA. Our results demonstrate that in the animal model used, ILK exhibits a decrease in expression at early stages of the fibrotic process and that a specific subset of fibroblasts is expressing ILK. The in vitro experiments suggested that ILK is not directly involved in E-cadherin downregulation and initiation of EMT (as is the case in renal fibrosis) but is involved in upregulation of vimentin. These results suggest that ILK is involved in lung fibrosis in a tissue-specific manner and raise the possibility to use it as a specific therapeutic target for lung fibrosis in the future.
Abstract: Our studies focus on ERp46, an endoplasmic reticulum (ER) component, and analyze its involvement in glucose toxicity and in insulin production. Differences in pancreatic beta-TC-6 cell proteome under conditions of low vs. high glucose were examined by proteomic approaches, including two-dimensional gel electrophoresis, image analysis, and mass spectrometry. Among differentially expressed proteins, ERp46, a novel endoplasmic reticulum component, was examined further. The expression of ERp46 in pancreatic sections was analyzed by immunocytochemistry, and high glucose-induced alterations of expression were evaluated in cultured beta-cells, in isolated pancreatic islets, and in the pancreas of db/db diabetic animals. Inhibition of ERp46 expression by siRNA was performed to study its role in insulin production, in secretion, and in ER stress. Proteomic analysis led to identification of 46 differentially expressed spots corresponding to 23 proteins. Since ERp46 is a novel protein with a possible crucial role in secretory cells, we further analyzed its role in beta-cell function. ERp46 expression is reduced in high glucose concentration in beta-TC-6 cells and in isolated murine islets. Further analysis revealed high expression of ERp46 in pancreatic islets compared with exocrine tissue. Interestingly, a marked decrease in ERp46 expression was found in the pancreatic islets of db/db mice. Most importantly, siRNA-mediated knockdown of ERp46 in cultured beta-cells led to a significant decrease in the insulin content; however, no alterations in insulin mRNA levels were observed under these conditions. In addition, reduced expression of ERp46 by siRNA increased the expression of CHOP and peIF2a, indicating development of ER stress. We conclude that ERp46 may be an important component in the phenomenon of "glucose toxicity" involved in insulin production at the posttranslational level.
Abstract: Tissue damage following injury leads to inflammation and fibrosis. To understand the molecular mechanisms and the proteins involved in the fibrotic process, we used the well-established unilateral ureteric obstruction rat model and we analyzed the alterations at early and late time intervals using a classical proteomic approach. Data analysis demonstrates a correlation between calreticulin up-regulation and progression of fibrosis. Calreticulin is involved in Ca++ homeostasis but has not been previously implicated in animal models of fibrosis. Proteomic analysis consistently revealed up-regulation of calreticulin in both early and late time intervals. These findings were further confirmed by biochemical and morphological approaches. Next, animal models of lung fibrosis (bleomycin-induced) and heart fibrosis (desmin-null) were examined. In the lung model, calreticulin expression was up-regulated from early time intervals, whereas in the heart model no change in the expression of calreticulin was observed. In addition, TGF-beta, a well known major contributing factor in several fibrotic processes, was found to up-regulate calreticulin in cultured human proximal tubule epithelial cells. The above observations suggest that calreticulin might be involved in fibrotic processes; however the mechanism(s) underlying its possible involvement are yet unresolved.
Abstract: The histone deacetylase inhibitor trichostatin A (TSA) is a promising agent for the treatment of certain types of cancers alone or in synergistic combination with other anticancer agents. One of the advantages of the use of histone deacetylase inhibitors, such as TSA, is that its effects have been found to be more potent toward cancer cells compared to normal cells. The effect of anticancer agents on the immune system, and on lymphocytes in particular, is of major importance to the success of anticancer regimens. In this respect, information documenting the effect of such agents on normal lymphocytes compared to malignant cells may be of significant value for the successful designing of clinical protocols. Moreover, the parameter of age may be a factor in the differential effects of such protocols. Histone deacetylase inhibitors lead to the accumulation of acetylated histones and, depending on the cell type, may induce either apoptosis, cell cycle arrest, or differentiation. Previous work from our lab has shown that TSA induces the accumulation of histone H4 acetylation and apoptosis in human peripheral blood lymphocytes. In light of the above, we have extended our investigation of the effects of TSA on human lymphocytes to include the parameter of age, which has not been previously studied. Our results show that TSA induces apoptosis of lymphocytes from donors of all age groups, but no age-related changes in the levels of apoptosis are observed.
Abstract: In the present study we investigated the age-related response of Phytohemaglutinin (PHA)-activated S phase human lymphocytes isolated from peripheral blood from donors of four different age groups, namely young (25-30 years), mid-aged (40-45 years), senior (60-65 years) and elderly (80-95 years) on the induction of the linker histone variant, H1 degrees and histone H4 acetylation after treatment with the very specific histone deacetylase (HDAC) inhibitor, trichostatin A (TSA). The cell system of peripheral blood lymphocytes is ideal for the study of H1 degrees induction since they do not synthesize this particular linker histone variant. Lymphocytes isolated from peripheral blood were activated with PHA (5 microg/10(6) cells/ml medium) and placed in culture for a duration of 72 h at which time cells are in the S phase. Forty-eight hours after inoculation, TSA (250 ng/10(6) cells/ml medium) was added to the cell cultures for a period of 24 h. Assays were performed 72 h after initiation of cultures. The results showed that the induction of H1 degrees after TSA treatment increased to a statistically significant degree in the elderly age group with respect to both the young and the mid-aged age groups. Moreover histone H4 acetylation was found to increase as a function of increasing donor age. A hyperacetylation pattern was observed even in the youngest age group analyzed. Specifically, the tetra-acetylated (H4.4) H4 form increased to a statistically significant degree with the concomitant decrease in the non-acetylated H4 for (H4.0) as a function of donor age. The other acetylated H4 forms (H4.1, H4.2, and H4.3) remained more or less constant, irrespective of donor age. These results show that the sensitivity of lymphocytes to TSA is enhanced with increasing donor age. Since to date, 11 class I and II HDACs have been isolated that have been found by other investigators to have differential responses to HDAC inhibitors, these findings may indicate that there is also a differential age-related response of certain HDACs or perhaps a senescent-specific HDAC. This line of research warrants further study.
Abstract: A pilot study was initiated in order to ascertain whether the age of the donor might affect either the induction of the expression of H1(0) or histone H4 acetylation by the very specific histone deacetylase inhibitor, trichostatin A. This was investigated in a cell system which normally does not express this linker histone variant, i.e. peripheral blood lymphocytes (PBL), which were obtained from donors of different ages (25-95 years). Forty-eight hours after activation by the mitogen phytohemaglutinin (PHA), 250 ng of trichostatin A per 10(6) cells per ml culture medium was added and cultured for an additional 24h. Assays were performed 72 h after initiation of cultures, i.e. during the S phase. It was found that in PBL, trichostatin A induced the expression of the linker histone variant, H1(0) as well as histone H4 acetylation, and, more importantly, that these effects were enhanced with increasing age of the donor. More specifically, under the influence of trichostatin A, PBL showed increasing H1(0) synthesis rates and increasing levels of histone H4 acetylation as a function of increasing age of the donor. Moreover, although trichostatin A induced an increasing expression of H1(0) with increasing age, it also concomitantly partially inhibited S phase total histone synthesis. This inhibition also increased as a function of increasing age of the donor.
