25 research outputs found
Cathepsins H and L in colorectal cancer
Cysteine cathepsins are important regulators and signaling molecules of an unimaginable number of biological processes while they also play an essential role in cancer progression, invasion and metastasis. The purpose of our study was: first to compare the expression levels of cathepsins H and L in the supernatants of colon cancer tissues from 74 patients versus the same enzymic expressions of the supernatants of the adjacent normal colorectal tissues and second to correlate our findings to the grade of the malignancy by using an enzyme-linked immunosorbent assay (ELISA). The results indicated that the cathepsins H and L of all malignant tissues presented significant higher expression’s values than the corresponding control. Specifically the concentration of cathepsin H that has been found increased significantly as malignancy proceeded, was higher than the corresponding control as following: 155% in B1 stage and 204,44% in D stage. Between the two investigated proteases cathepsin L has showed the greatest increase, which in D stage was 261,03% higher than the corresponding control. According to these results, the expression of cysteine proteases H and L could be of critical value in the diagnosis and progression of colon cance
Cytogenetic behaviour of crocin on cultured lymphocytes from leukemic patients
Crocin is isolated from saffron, an important spice rich in carotenoids obtained from the stigmas of Crocus sativus L, commonly consumed all around the world and used as a medical drug to treat numerous diseases. In the present work a comparative study of the cytogenetic behaviour of crocin between cultured lymphocytes from chronic lymphocytic leukemic patients as well as from healthy individuals was undertaken in order to test the hypothesis that the sister chromatid exchange assay in vitro can be used for the prediction of the in vivo tumor response to the potential chemotherapeutic action of crocin. Sister chromatid exchanges (SCEs) and proliferation rate index (PRI) were evaluated in cultured lymphocytes from peripheral blood of all donors. Results showed that all tested crocin solutions didn’t cause remarkable changes to the PRI values of lymphocytes neither of the leukemic patients, nor of healthy individual. Contrariwise, after crocin affection a statistically significant decrease of the SCEs frequency of lymphocytes of leukemic patients had been observed (p<0,001, t-test) whereas the SCEs of the healthy donor’s cells presented slight, but not statistically significant increase. Our results indicate that crocin did not prove to be cytostatic in the tested concentrations, but it mainly reduced significantly the DNA damages along with being demonstrated as cytoprotectiv
Influence of conception and delivery mode on stress response marker Oct4B1 and imprinted gene expression related to embryo development: A cohort study
Background: Recent scientific data support that the mode of conception and delivery may influence epigenetic regulation and therefore embryo development. Octamer-binding transcription factor 4-B1 (OCT4B1), a novel variant of OCT4 with yet unknown biological function, is suggested to have a potential role in mediating cellular stress response. Furthermore, Insulinlike Growth Factor 2 (IGF2), Mesoderm-specific Transcript (MEST) and paternally expressed gene 10 (PEG10) are genes known as imprinted and are regulated via means of epigenetic regulation. The influence of delivery mode and conception on epigenetic regulation is an active research field.
Objective: Our aim was to correlate the expression level of Oct4B1 and the expression and methylation level of IGF2, MEST, and PEG10 imprinted genes with the mode of delivery and conception in the umbilical cord blood of newborns.
Materials and Methods: Samples of umbilical cord blood from infants born after vaginal delivery, caesarean section (CS) with the infant in cephalic position and CS due to breech position were examined. Furthermore, the investigation included infants conceived through means of assisted reproductive technology.
Results: No statistically significant differences were found in mRNA expression levels between different modes of conception and delivery (p = 0.96). Oct4B1, IGF2, MEST, and PEG10 expression levels do not seem to be significantly affected by different modes of conception and delivery.
Conclusion: These results indicate that the expression and methylation patterns of Oct4B1, IGF2, MEST and PEG10 in umbilical cord blood are not affected by the conception and delivery mode.
Key words: Conception, Fertilization in vitro, Genomic imprinting, Fetal blood
SARS-CoV-2 Molecular Transmission Clusters and Containment Measures in Ten European Regions during the First Pandemic Wave
International audienceBackground: The spatiotemporal profiling of molecular transmission clusters (MTCs) using viral genomic data can effectively identify transmission networks in order to inform public health actions targeting SARS-CoV-2 spread. Methods: We used whole genome SARS-CoV-2 sequences derived from ten European regions belonging to eight countries to perform phylogenetic and phylodynamic analysis. We developed dedicated bioinformatics pipelines to identify regional MTCs and to assess demographic factors potentially associated with their formation. Results: The total number and the scale of MTCs varied from small household clusters identified in all regions, to a super-spreading event found in Uusimaa-FI. Specific age groups were more likely to belong to MTCs in different regions. The clustered sequences referring to the age groups 50–100 years old (y.o.) were increased in all regions two weeks after the establishment of the lockdown, while those referring to the age group 0–19 y.o. decreased only in those regions where schools’ closure was combined with a lockdown. Conclusions: The spatiotemporal profiling of the SARS-CoV-2 MTCs can be a useful tool to monitor the effectiveness of the interventions and to reveal cryptic transmissions that have not been identified through contact tracing
DNA methylation and gene expression patterns in umbilical cord blood samples
Genomic imprinting has a central role in human development and is essential to placental functions that regulate normal fetal growth. Genes that are subject to genomic imprinting are expressed in a parent-of-origin specific manner and may influence fetal growth through effects on placental function and nutrient metabolism. Dysregulation of imprinted gene methylation has been repeatedly proposed as a key molecular mechanism linking developmental exposures with adverse health outcomes later in life. Recent studies have elucidated the role of imprinted genes, including IGF2, MEST and PEG10, in determining fetal growth and found support for the importance of genomic imprinting in fetal development. IGF2, MEST and PEG10 imprinted genes have a broad developmental effect on fetal growth and birth weight variation. Impaired methylation and expression of these genes is associated to adverse fetal growth, pre-term birth, low birth weight, metabolic disorders and cognitive impairment. Several environmental stressors, including birth stress and conception through assisted reproductive technologies (ART), can affect the pattern of the abovementioned genes, resulting in differential DNA methylation/expression levels and increased risk of disease. Vaginal delivery (VD) of infants exposes them to stressors absent in caesarean section (CS), such as a surge of stress hormones which in turn can trigger cytokine and hormonal cascades preparing the infant for extrauterine life. Concerning stress at cellular level, an isoform of Oct4 transcription factor, Oct4B1, has emerged as a putative cell stress marker, resulting in differential expression levels under altered stress conditions. Manipulations during ART, including handling of gametes, ovarian stimulation and in vitro culture, represent artificial interventions, which coincide with critical windows for epigenetic reprogramming and expose the developing epigenome to stress factors that may result in aberrant establishment and maintenance of genomic imprints, leading to an increase in congenital malformations and imprinting disorders. Given that epigenetic modification is sensitive to environmental factors, such as various stressors, concerns are raised about future implications of the increasing prevalence in elective CS deliveries and the use of ART.In the present study we investigated the expression level of Oct4B1 and HERV-W1, and the expression and methylation status of IGF2, MEST and PEG10 imprinted genes in samples of umbilical cord blood (UCB) of newborns with different modes of conception and delivery. UCB samples were collected during delivery time from 40 enrolled participants. The samples were subdivided in 4 groups comprised of 10 participants each. The groups examined were VD (control group), CS with cephalic projection of the embryo and CS with breech embryo projection. The fourth consisted of infants conceived through ART (IVF and ICSI). This is the first study on the expression and methylation of those genes that correlates them to embryo presentation during CS and the first to evaluate the Oct4B1 levels in UCB samples.The results indicate that different modes of conception and delivery do not alter significantly the mRNA expression levels for Oct4B1 (p=0,58), IGF2 (p=0,96), MEST (p=0,75) and PEG10 (p=0,37) in UCB. There was a trend for increased expression of PEG10 in the CS with breech embryo projection group, a finding that warrants further investigation in broader sample studies. These results could be attributed to the small sample size available, but also to the extremely strict inclusion criteria that were employed. HERV-W1 showed no expression in our samples. Methylation analysis revealed the presence of both methylated and unmethylated alleles for IGF2, MEST and PEG10 imprinted genes, with no methylation differences reported between groups. Methylation analysis was not possible for Oct4B1 due to the existence of alternative promoters for this isoform, unknown so far. Methylation status of all genes is in consistence with non statistical differences in expression. These results are the first reported in cephalic and breech presentation CS concerning these specific genes. As far as the ART group is concerned, our results are consistent with some of the previous reports. However, there are other studies reporting altered DNA methylation and expression levels of these genes after ART treatments. It is necessary to understand health risks and underlying molecular mechanisms of ART interventions, for the purpose of increasing the safety of these techniques. Thus, the contradictory literature results call for caution and for larger studies. This doctorate thesis aims to stress the importance of evaluating the effect of environmental stressors on the epigenome. It can be considered as a starting point for more thorough investigations on the role of imprinted genes and Oct4B1 isoform on the regulation of human reproduction.Το γονιδιακό εντύπωμα παίζει σημαντικό ρόλο στην ανάπτυξη του ανθρώπου και είναι απαραίτητη για τη λειτουργία του πλακούντα και τη ρύθμιση της εμβρυϊκής ανάπτυξης. Τα γονίδια που υπόκεινται σε γονιδιακή εντύπωση εκφράζονται μονο-αλληλικά, αναλόγως του γονέα από τον οποίο κληρονομούνται και επηρεάζουν την εμβρυϊκή ανάπτυξη μέσω επιδράσεων στη λειτουργία του πλακούντα και του μεταβολισμού των θρεπτικών συστατικών. Η λανθασμένη μεθυλίωση των εντυπωμένων γονιδίων έχει επανειλημμένως προταθεί ως ο βασικός μοριακός μηχανισμός που συνδέει τις αρνητικές επιδράσεις περιβαλλοντικών παραγόντων με την εμφάνιση προβλημάτων υγείας στη διάρκεια της ζωής. Τα αποτελέσματα πρόσφατων μελετών έχουν αποσαφηνίσει το ρόλο πολλών εντυπωμένων γονιδίων, συμπεριλαμβανομένων των IGF2, MEST και PEG10, στην εμβρυϊκή ανάπτυξη και τονίζουν τη σημασία του γονιδιακού εντυπώματος στη σωστή λειτουργία και ανάπτυξη του οργανισμού. Τα IGF2, MEST and PEG10 εντυπωμένα γονίδια διαδραματίζουν σημαντικό ρόλο στην ανάπτυξη του εμβρύου και στον καθορισμό του βάρους γέννησης. Λανθασμένη έκφραση και μεθυλίωση αυτών των γονιδίων σχετίζεται με ανωμαλίες στην ανάπτυξη, πρόωρο τοκετό, χαμηλό βάρος γέννησης, εμφάνιση μεταβολικών συνδρόμων και νοητική υστέρηση. Η επίδραση πολλών περιβαλλοντικών παραγόντων, όπως είναι το στρες κατά τον τοκετό και η σύλληψη μέσω εφαρμογής τεχνικών υποβοηθούμενης αναπαραγωγής (ART), μπορούν να επηρεάσουν το επιγενετικό πρότυπο των ανωτέρω γονιδίων και να οδηγήσουν σε αλλαγές στα επίπεδα μεθυλίωσης/έκφρασης με αποτέλεσμα την εμφάνιση ασθενειών. Κατά τη διάρκεια του φυσιολογικού τοκετού το έμβρυο εκτίθεται σε παράγοντες που εκλείπουν κατά την καισαρική τομή, όπως είναι το υψηλό κύμα ορμονών του στρες, το οποίο πυροδοτεί την παραγωγή κυτοκινών και άλλων ορμονών, προετοιμάζοντας το νεογνό για τη ζωή έξω από τη μήτρα. Σε κυτταρικό επίπεδο, η ισομορφή Oct4B1 του Oct4 μεταγραφικού παράγοντα φαίνεται να αποτελεί δείκτη απόκρισης του κυττάρου στο στρες, παρουσιάζοντας αυξημένα επίπεδα έκφρασης κάτω από στρεσσογόνες συνθήκες. Οι χειρισμοί και οι διαδικασίες κατά την εξωσωματική γονιμοποίηση, συμπεριλαμβανομένων του χειρισμού των γαμετών, της ωοθηκικής διέγερσης και της in vitro καλλιέργειας, αποτελούν τεχνητές παρεμβάσεις, που συμπίπτουν χρονικά με κρίσιμα στάδια επιγενετικής ρύθμισης και εκθέτουν το αναπτυσσόμενο επιγονιδίωμα σε στρεσσογόνους περιβαλλοντικούς παράγοντες που μπορεί να οδηγήσουν σε λανθασμένη δημιουργία και διατήρηση του γενωμικού εντυπώματος. Δεδομένου ότι οι επιγενετικές διεργασίες είναι ευαίσθητες στην επίδραση περιβαλλοντικών παραγόντων, η αύξηση της συχνότητας των καισαρικών τομών και της εφαρμογής τεχνικών υποβοηθούμενης αναπαραγωγής έχει δημιουργήσει πολλές ανησυχίες για τις μελλοντικές συνέπειές τους στην υγεία των ατόμων.Στην παρούσα διδακτορική διατριβή, πραγματοποιήθηκε ανάλυση των επιπέδων έκφρασης της Oct4B1 ισομορφής και του μεταθετού στοιχείου HERV-W1, καθώς και των επιπέδων έκφρασης και μεθυλίωσης των IGF2, MEST και PEG10 εντυπωμένων γονιδίων σε δείγματα ομφαλοπλακουντιακού αίματος (UCB) νεογνών που γεννήθηκαν ύστερα από διαφορετικό τρόπο σύλληψης και τοκετού. Η μελέτη περιελάμβανε 4 διαφορετικές ομάδες μελέτης με 10 UCB δείγματα ανά ομάδα. Οι ομάδες μελέτης αποτελούνταν από νεογνά φυσιολογικού τοκετού (control group), καισαρικής τομής κεφαλικής προβολής και καισαρικής τομής ισχιακής προβολής. Η τέταρτη ομάδα αποτελούνταν από νεογνά που γεννήθηκαν ύστερα από την εφαρμογή ART μεθόδων. Η συγκεκριμένη μελέτη αποτελεί την πρώτη αναφορά που προσπαθεί να συσχετίσει την έκφραση και μεθυλίωση των ανωτέρω γονιδίων με την προβολή το εμβρύου κατά την καισαρική τομή, καθώς και την πρώτη μελέτη που προσπαθεί να αξιολογήσει την έκφραση της Oct4B1 σε UCB δείγματα.Τα αποτελέσματα της διατριβής υποδεικνύουν ότι ο διαφορετικός τρόπος σύλληψης και τοκετού δεν προκαλεί στατιστικώς σημαντική αλλαγή στα επίπεδα έκφρασης των Oct4B1 (p=0,58), IGF2 (p=0,96), MEST (p=0,75) και PEG10 (p=0,37) γονιδίων στο ομφαλοπλακουντιακό αίμα. Υπήρξε μια τάση για αυξημένη έκφραση του PEG10 γονιδίου στην ομάδα καισαρικής τομής με κεφαλική προβολή του εμβρύου, αλλά το αποτέλεσμα αυτό πρέπει να αξιολογηθεί σε μελέτες με μεγαλύτερο μέγεθος δείγματος. Τα αρνητικά αυτά αποτελέσματα μπορούν να αποδοθούν στο μικρό μέγεθος δείγματος, αλλά και στα αυστηρά κριτήρια επιλογής που εφαρμόστηκαν ώστε τα αποτελέσματα να είναι πιο αξιόπιστα. Για το γονίδιο HERV-W1 δεν παρατηρήθηκε έκφραση στα δείγματα της μελέτης μας. Η ανάλυση της μεθυλίωσης του DNA ανέδειξε την παρουσία τόσο των μη μεθυλιωμένων όσο και των μεθυλιωμένων αλληλομόρφων των IGF2, MEST και PEG10 εντυπωμένων γονιδίων, χωρίς να παρουσιάζονται διαφορές μεταξύ των διαφορετικών ομάδων μελέτης. Η ανάλυση της μεθυλίωσης της Oct4B1 δεν ήταν δυνατή, καθώς η συγκεκριμένη ισομορφή μεταγράφεται από διαφορετικούς υποκινητές, οι οποίοι είναι άγνωστοι μέχρι στιγμής. Τα αποτελέσματα της μεθυλίωσης όλων των γονιδίων βρίσκονται σε συμφωνία με τα αντίστοιχα αποτελέσματα έκφρασης. Τα ανωτέρω αποτελέσματα είναι τα πρώτα που αναφέρονται σε περιστατικά καισαρικής τομής κεφαλικής και ισχιακής προβολής και αφορούν τα συγκεκριμένα γονίδια. Όσον αφορά την ομάδα των νεογνών που γεννήθηκαν ύστερα από την εφαρμογή τεχνικών υποβοηθούμενης αναπαραγωγής, τα αποτελέσματά μας συμφωνούν με προηγούμενες βιβλιογραφικές αναφορές. Παρόλα αυτά, υπάρχουν και μελέτες που αναφέρουν αλλαγές στα επίπεδα μεθυλίωσης DNA και έκφρασης αυτών των γονιδίων ύστερα από εφαρμογή ART τεχνικών. Κρίνεται απαραίτητο να κατανοήσουμε τους υποκείμενους μηχανισμούς δράσης των ART τεχνικών, προκειμένου να αυξηθεί η ασφάλεια αυτών των τεχνικών και να προληφθούν πιθανές επιπτώσεις στην υγεία. Γι αυτόν το λόγο, πρέπει να αποσαφηνιστούν τα αντικρουόμενα αποτελέσματα που υπάρχουν στη διεθνή βιβλιογραφία μέσω μεγαλύτερων και καλύτερα οριοθετημένων μελετών. Η παρούσα διδακτορική διατριβή έχει ως στόχο να τονίσει τη σημασία της αξιολόγησης των περιβαλλοντικών επιδράσεων στο επιγονιδίωμα. Θα μπορούσε να αποτελέσει ένα πρώτο βήμα για περισσότερο διεξοδικές αναλύσεις όσον αφορά το ρόλο των εντυπωμένων γονιδίων και της Oct4B1 ισομορφής στη ρύθμιση της ανθρώπινης αναπαραγωγής
Bioclimatic design, solar passive systems and other techniques of energy saving in the building sector
196 σ.Στην εργασία αυτή περιγράφονται οι βασικές αρχές του βιοκλιματικού σχεδιασμού και η λειτουργία των ηλιακών παθητικών συστημάτων άμεσου και έμμεσου ηλιακού κέρδους για την επίτευξη θέρμανσης και δροσισμού στα κτήρια. Επίσης, αναφέρονται συστήματα θερμικής προστασίας του κελύφους, καθώς επίσης και μέθοδοι φυσικού δροσισμού και αερισμού. Αναλύονται τρόποι αξιοποίησης του φυσικού φωτισμού, καθώς και η σπουδαιότητα χρήσης οικολογικών δομικών υλικών και υλικών νέων τεχνολογιών. Τέλος, αναφέρονται τεχνικές εξοικονόμησης ενέργειας και παρουσιάζεται μια παραμετρική μελέτη σχετικά με τη λειτουργία του κλιματισμού με ψυχόμενα δομικά στοιχεία.In this project, the basic bioclimatic pricinples are described, as well as the function of direct and indirect solar pssive systems for the achievement of building's cooling and heating. Furthermore, systems of thermal protection of the building envelope and methods of natural cooling and natural ventilation are mentioned. Ways of exploiting the natural light, as well as, the importance of the usage of ecological and new building materials are discussed. Finally, techniques of energy saving are mentioned and an analysis related to the cooling panels' function is presented.Μαρία Ι. Αργυράκ
Differential expression of IL-17, 22 and 23 in the progression of colorectal cancer in patients with K-ras mutation: Ras signal inhibition and crosstalk with GM-CSF and IFN-γ.
Recent studies have suggested that aberrant K-ras signaling is responsible for triggering immunological responses and inflammation-driven tumorigenesis. Interleukins IL-17, IL-22, and IL-23 have been reported in various types of malignancies, but the exact mechanistic role of these molecules remains to be elucidated. Given the role of K-ras and the involvement of interleukins in colorectal tumorigenesis, research efforts are reported for the first time, showing that differentially expressed interleukin IL-17, IL-22, and IL-23 levels are associated with K-ras in a stage-specific fashion along colorectal cancer progression. Specifically, a) the effect of K-ras signaling was investigated in the overall expression of interleukins in patients with colorectal cancer and healthy controls, and b) an association was established between mutant K-ras and cytokines GM-CSF and IFN-γ. The results indicate that specific interleukins are differentially expressed in K-ras positive patients and the use of K-ras inhibitor Manumycin A decreases both interleukin levels and apoptosis in Caco-2 cells by inhibiting cell viability. Finally, inflammation-driven GM-CSF and IFN-γ levels are modulated through interleukin expression in tumor patients, with interleukin expression in the intestinal lumen and cancerous tissue mediated by aberrant K-ras signaling. Collectively, the findings a) indicate that interleukin expression is influenced by ras signaling and specific interleukins play an oncogenic promoter role in colorectal cancer, highlighting the molecular link between inflammation and tumorigenesis, and b) accentuate the interwoven molecular correlations as leads to new therapeutic approaches in the future
Environmental Fate of Trace Elements in Depositional Sediments after Flashflood Events: The Case of Mandra Town in Greece
Flash floods are one of the harshest natural hazards, having a wide range of substantial impacts for human and environmental health in the short-term and long-term. On 15 November 2017, a high-intensity storm caused a catastrophic flash flood event in the town of Mandra, a western, outer suburb of the Athens Metropolitan Area in Greece. In this study, we determine the aqua regia extractable concentrations of trace elements in residual sediments and associated soils after the flash flood and evaluate the fractionation of contaminants in geochemical compartments. Geochemical data are coupled with physicochemical parameter measurements and mineralogy to identify possible factors explaining the variability of trace element concentrations, while a dilute acid extraction is used to monitor changes of the reactive fraction of the trace elements over the term of 1 year following the flood event. Aqua regia concentrations in flood-deposited sediments reached values of 1 mg/kg (Cd), 24 mg/kg (Co), 183 mg/kg (Cr), 599mg/kg (Cu), 1080 mg/kg (Mn), 195 mg/kg (Ni), 122 mg/kg (Pb) and 945 mg/kg (Zn). Multivariate statistical techniques classified the elements according to their natural or anthropogenic origin. Trace elements of geogenic origin (As, Co, Cr, Mn, Ni) dominate in flood deposited material. The cluster of anthropogenic elements (Cd, Cu, Pb, Zn,) shows significant correlation with total organic carbon and magnetic susceptibility, while a significant seasonal variation has been observed for total organic carbon, Cd and Mn contents in the deposited sediments. Results allow a better understanding of the distribution of elements in the surface cover during and after catastrophic events in urban areas and provide useful information on the long-term exposure of the residents
Strategies toward catalytic biopolymers: Incorporation of tungsten in alginate aerogels
We report the synthesis of W-doped biopolymer aerogels with potential applications to catalysis. The
biopolymers were based on alginate, a cost-efficient natural material, and were prepared in environmentally
friendly water/ethanol solutions. Gelation of alginate was induced by crosslinking with Ca2+. The
resulting wet-gels were impregnated with an ethanolic solution of the ditungsten complex
[W2(μ-OEt)2(OEt)2(EtOH)2Cl4] ({W =W}8+) and were dried with supercritical fluid (SCF) CO2 to yield
W-doped alginate aerogels containing 10% w/w tungsten. Dry materials were characterized with FTIR,
SEM/EDS, TGA, N2 porosimetry and He pycnometry. The bulk densities were low (<0.1 g cm-3), porosities
were high (96% v/v), as well as the BET surface areas (380 m2/g). Pyrolysis of those aerogels at 800 oC
under Ar yielded carbon along with a mixture of calcium tungstates, i.e., CaWO4 and Ca3WO6 (weight
ratio: 70:30), while pyrolysis under O2 yielded the same tungstates, but with a different weight ratio
(10:90). This can be a new process for Ca3WO6, which, due to its ordered double perovskite structure,
is ideal for doping with metal ions, at relatively low temperature (800 oC versus >1000 oC in the
literature)
Immunohistochemical analysis of IL-17, IL-22, and IL-23 in human colon biopsies.
<p>Immunohistochemical staining of (<b>A</b>) IL-17, (<b>B</b>) IL-22, and (<b>C</b>) IL-23 in colon biopsies from patients with colorectal cancer. Paraffined sections of human colon biopsies were obtained from patients with colorectal cancer (<b>b</b>), and non-cancerous tissue (<b>a</b>). Human IL-17, IL-22, and IL-23, were detected using anti-human monoclonal antibodies from Santa Cruz. Staining with mouse IgG1 isotype was used as the negative control. Stained tumor cells are shown at a final magnification of ×400.</p