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Nikos Papakonstantinou Stavroula Ntoufa Elisavet Chartomatsidou Giorgio Papadopoulos Artemis Hatzigeorgiou Achiles Anagnostopoulos Katerina Chlichlia Paolo Ghia Marta Muzio Chrysoula Belessi Kostas Stamatopoulos 《Molecular medicine (Cambridge, Mass.)》2013,19(1):115-123
Critical processes of B-cell physiology, including immune signaling through the B-cell receptor (BcR) and/or Toll-like receptors (TLRs), are targeted by microRNAs. With this in mind and also given the important role of BcR and TLR signaling and microRNAs in chronic lymphocytic leukemia (CLL), we investigated whether microRNAs could be implicated in shaping the behavior of CLL clones with distinct BcR and TLR molecular and functional profiles. To this end, we examined 79 CLL cases for the expression of 33 microRNAs, selected on the following criteria: (a) deregulated in CLL versus normal B-cells; (b) differentially expressed in CLL subgroups with distinct clinicobiological features; and, (c) if meeting (a) + (b), having predicted targets in the immune signaling pathways. Significant upregulation of miR-150, miR-29c, miR-143 and miR-223 and downregulation of miR-15a was found in mutated versus unmutated CLL, with miR-15a showing the highest fold difference. Comparison of two major subsets with distinct stereotyped BcRs and signaling signatures, namely subset 1 [IGHV1/5/7-IGKV1(D)-39, unmutated, bad prognosis] versus subset 4 [IGHV4-34/IGKV2-30, mutated, good prognosis] revealed differences in the expression of miR-150, miR-29b, miR-29c and miR-101, all down-regulated in subset 1. We were also able to link these distinct microRNA profiles with cellular phenotypes, importantly showing that, in subset 1, miR-101 downregulation is associated with overexpression of the enhancer of zeste homolog 2 (EZH2) protein, which has been associated with clinical aggressiveness in other B-cell lymphomas. In conclusion, specific miRNAs differentially expressed among CLL subgroups with distinct BcR and/or TLR signaling may modulate the biological and clinical behavior of the CLL clones. 相似文献
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Theodora?Koromila Panagiotis?Georgoulias Zoe?Dailiana Evangelia?E?Ntzani Stavroula?Samara Chris?Chassanidis Vassiliki?Aleporou-Marinou Panagoula?KolliaEmail author 《Human genomics》2013,7(1):21
Background
Osteoporosis has a multifactorial pathogenesis characterized by a combination of low bone mass and increased fragility. In our study, we focused on the effects of polymorphisms in CER1 and DKK1 genes, recently reported as important susceptibility genes for osteoporosis, on bone mineral density (BMD) and bone markers in osteoporotic women. Our objective was to evaluate the effect of CER1 and DKK1 variations in 607 postmenopausal women. The entire DKK1 gene sequence and five selected CER1 SNPs were amplified and resequenced to assess whether there is a correlation between these genes and BMD, early menopause, and bone turnover markers in osteoporotic patients.Results
Osteoporotic women seem to suffer menopause 2 years earlier than the control group. The entire DKK1 gene sequence analysis revealed six variations. There was no correlation between the six DKK1 variations and osteoporosis, in contrast to the five common CER1 variations that were significantly associated with BMD. Additionally, osteoporotic patients with rs3747532 and rs7022304 CER1 variations had significantly higher serum levels of parathyroid hormone and calcitonin and lower serum levels of osteocalcin and IGF-1.Conclusions
No significant association between the studied DKK1 variations and osteoporosis was found, while CER1 variations seem to play a significant role in the determination of osteoporosis and a potential predictive role, combined with bone markers, in postmenopausal osteoporotic women.4.
Stavroula Samara Zoe Dailiana Sokratis Varitimidis Christos Chassanidis Theodora Koromila Konstantinos N. Malizos Panagoula Kollia 《Molecular biology reports》2013,40(7):4465-4472
Avascular necrosis (AVN) is a disorder of the bone repair process which usually results in femoral head (FH) destruction. Bone morphogenetic proteins (BMPs) are the key proteins regulating bone remodelling and healing. BMPs gene expression levels were analyzed in the normal and necrotic sites of osteonecrotic FHs. Quantitative RT-PCR for BMP-2, -4, -6, -7 genes was performed in bone tissue samples from 47 osteonecrotic FHs. Protein levels of BMP-2, -4, -6 were estimated by Western Blot. Statistical analysis was performed using the Wilcoxon signed rank test. BMP-2 and BMP-6 mRNA levels were higher in the normal than the necrotic site (normal/necrotic: 16.8/6.8 and 1.75/1.64, respectively). On the contrary, BMP-4 mRNA levels were higher in the necrotic (0.75) than the normal (0.62), while BMP-7 mRNA levels were extremely low. At the protein level, BMP-2 continued to have a higher expression in the normal region (normal/necrotic: 0.67/0.64). BMP-4 and -6 were detected at higher levels in the necrotic site (normal/necrotic: 0.51/0.61 for BMP-4, 0.51/0.56 for BMP-6), while BMP-7 was not detectable. Different BMP levels between the normal and necrotic site, as well as discrepancies between the gene and protein expression pattern suggest a different regulation mechanism for BMPs between the two regions of FHs. The understanding of the expression pattern and the correlation of BMPs could lead to a more successful use in the prevention and treatment of AVN. 相似文献
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Kovala-Demertzi D Galani A Demertzis MA Skoulika S Kotoglou C 《Journal of inorganic biochemistry》2004,98(2):358-364
The synthesis and characterization of copper(II) complexes with a potent non-steroidal anti-inflammatory drug, tolfenamic acid, Htolf, with formula [Cu(tolf)(2)L](2) (where L is H(2)O or DMF, N,N-dimethylformamide) were investigated. The crystal and molecular structure of [Cu(tolf)(2)(DMF)](2) was reported. Crystallographic data are as follows: monoclinic system, space group P2(1)/n with cell constants a=9.068(2) A, b=14.514(3) A, c=22.826(4) A, V=2948.9(10) A(3) and Z=2. The crystal structure consists of binuclear, quadruply bridged neutral molecule with a Cu-Cu bond length of 2.6075(19) A. The complex is self-assembled via C-H-pi intermolecular stacking interactions. Spectroscopic and electrochemical studies were reported. The superoxide dismutase activity is measured and compared with those of superoxide dismutase enzyme, SOD, the free ligand and related copper complexes with non-steroidal anti-inflammatory drugs, NSAIDs. IC(50) value was measured by the Fridovich test (1.97+/-0.17 microM), which showed that [Cu(tolf)(2)L](2) is a good superoxide scavenger. 相似文献
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The crystal structure of the Escherichia coli Vsr endonuclease bound to a C(T/G)AGG substrate revealed that the DNA is held by a pincer composed of a trio of aromatic residues which intercalate into the major groove, and an N-terminus alpha helix which lies across the minor groove. We have constructed an N-terminus truncation (Delta14) which removes most of the alpha helix. The mutant is still fairly proficient in mediating very short patch repair. However, its endonuclease activity is considerably reduced and, in contrast to that of the wild type protein, cannot be stimulated by MutL. We had shown previously that excess Vsr in vivo causes mutagenesis, probably by inhibiting the participation of MutL in mismatch repair. The Delta14 mutant has diminished mutagenicity. In contrast, four enzymatically inactive mutants, with intact N-termini, are as mutagenic as the wild type protein. On the basis of these results we suggest that MutL causes a conformational change in the N-terminus of Vsr which enhances Vsr activity, and that this functional interaction between Vsr and MutL decreases the ability of MutL to carry out mismatch repair. 相似文献
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Baritaki S Zafiropoulos A Georgopoulos E Souris S Krambovitis E 《Cancer immunology, immunotherapy : CII》2001,50(2):109-114
It has been demonstrated that IgG antibodies can be generated to self-antigen peptides as well as against viral antigens
by an antigen-specific in vitro immunization system of resting human peripheral B-lymphocytes. Using a synthetic peptide from
the consensus variable tandem-repeat region of the MUC3 mucin (TSSITTTGTTSHSTPSP) as the B cell epitope, we immunized blood
donor B-lymphocytes in vitro and tested for MUC3-specific antibodies by ELISA. After the primary activation step all antibodies
were IgM. At the end of the secondary immunization step we obtained 1.8% (21/1138) of the cultures with IgG-switched antibodies.
In a competitive inhibition ELISA using the MUC1, MUC2, MUC3, MUC4 and PIP2 peptides, only one culture (F8.1) gave satisfactory
specific inhibition. Using this antibody in fluorometric studies, it stained cells from two colon carcinoma cell lines predominantly
in the cytoplasm, whereas those from a breast cancer cell line stained predominantly the cell surface. In a preliminary immunohistological
evaluation with formalin-fixed sections, the antibody appeared to moderately stain colon sections, but not breast sections
or lymph node. This method of in vitro immunization may be a useful tool in generating IgG antibodies specific to self-antigens
and could find applications in tumour targeting and immunotherapy.
Received: 12 October 2000 / Accepted: 11 January 2001 相似文献
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Aphrodite Kantsa Stavroula Sotiropoulou Michail Vaitis Theodora Petanidou 《化学与生物多样性》2015,12(10):1466-1480
Knowing plant volatile chemodiversity and its distribution is essential in order to study biological processes, to estimate the plants' value in use, and to establish sustainable exploitation practices. Yet, attempts to collect and assess data on scent diversity and properties in well‐defined geographical areas are rare. Here, we developed a geo‐referenced database of the plant volatilome in Greece by consolidating the results included in 116 research articles published in the last 25 years. The data set compiled includes 999 volatile organic compounds distributed into 178 plant taxa, 59 genera, and 19 families. Distillation is the acquisition method almost exclusively used, whereas headspace techniques that would allow the study of subtle ecological processes are generally lacking. Sesquiterpenes show the greatest richness of compounds, followed by monoterpenes and aliphatics. We assess the volatility of the compounds using the normal boiling point (nBP) as its reverse indicator, and we present the volatility spectra of the blends of the genera studied. Mean nBPs vary among genera, with maximal differences as wide as 118.4°. Finally, we feature basic chemodiversity maps for three aromatic plants, and discuss their importance and prospects as a special case of natural resources maps. 相似文献
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Erica Rose Denhoff Carly E. Milliren Sarah D. de Ferranti Sarah K. Steltz Stavroula K. Osganian 《PloS one》2015,10(10)
Background
One of the most difficult aspects of conducting clinical research is the ability to successfully recruit participants. Pediatric clinical research presents unique recruitment challenges that relate to the need for parental consent on behalf of a minor, child assent, and school attendance. Yet, this has been less well studied. We conducted a survey of investigators performing human subjects research in a single large academic pediatric hospital to better understand characteristics of studies with successful recruitment.Methods
We conducted a web-based survey from September 2011 to December 2011 of all principal investigators with an Institutional Review Board approved human subjects protocol at Boston Children’s Hospital, a pediatric Academic Medical Center. The survey captured various characteristics of the protocols including study design, staffing, resources, and investigator experience and training as well as respondents’ perceived barriers and facilitators to recruitment. We used chi square tests and Mantel-Haenszel test for linear trend to examine the relationship between selected predictor variables and the binary outcome of successful vs. unsuccessful recruitment and multivariable logistic regression analyses to examine the simultaneous influence of potential predictors on each outcome.Results
Among the 349 eligible investigators, 52% responded to the survey, and 181 with valid data were included in the analyses. Two-thirds of the 87 protocols closed to enrollment reached 80% or more of their target enrollment, whereas, only one-third of the 94 protocols actively recruiting were meeting 80% of their target. Recruitment method appeared to be the only significant and independent factor associated with achieving 80% or more of target enrollment in closed to enrollment protocols. Closed to enrollment protocols that used recruitment in person were 4.55 times (95% CI 1.30 to 15.93; p = 0.02) more likely to achieve 80% or more of their target enrollment when compared to those that used other recruitment methods. Other potentially modifiable factors such as number of study visits, study duration and investigator experience were suggestive of being meaningfully related to recruitment.Conclusion
Recruiting in person may promote reaching an acceptable target enrollment in pediatric as well as adult clinical research. Future research is needed on larger and more diverse samples to gain a better understanding of how the characteristics and qualifications of the individuals who conduct recruitment influence participant enrollment as well as how best to approach patient and families for their participation. 相似文献10.