30 research outputs found
Identification of a new hobo element in the cabbage moth, Mamestra brassicae (Lepidoptera).
A complete hobo-like element, called Mbhobo, was identified in the cabbage moth, Mamestra brassicae. This element has a high sequence similarity to the HFL1 hobo element of Drosophila melanogaster. Amplification of Mbhobo termini indicated that transposition occurred into a 5’-GTGGGTAC-3’ target sequence that was duplicated upon insertion. This target site conforms to the consensus sequence established for the insertion sites of insect hAT elements. Mbhobo has a single 1935 bp long ORF with significant homology to the D. melanogaster HFL1 hobo transposase. FISH experiments evidenced Mbhobo clusters located in heterochromatic regions of Z and W sex chromosomes and in heterochromatic areas of chromosome pair 10
Composition and Epigenetic Markers of Heterochromatin in the Aphid Aphis nerii (Hemiptera: Aphididae).
A detailed karyotype analysis of the oleander aphid Aphis nerii focusing on the distribution, molecular composition and epigenetic modifications of heterochromatin was done in order to better understand the structure and evolution of holocentric/holokinetic chromosomes in aphids. The female karyotype (2n = 8) consisted of 3 pairs of autosomes and a pair of X chromosomes that were the longest elements in the karyotype and carried a single, terminally located nucleolar organizer region. Males showed 2n = 7 chromosomes due to the presence of a single X chromosome. Heterochromatin was located in the X chromosomes only and consisted of 4 satellite DNAs that have been identified. A. nerii constitutive heterochromatin was enriched in mono-, di- and tri-methylated H3 histones and HP1 proteins but, interestingly, it lacked DNA methylation that was widespread in euchromatic chromosomal regions. These results suggest that aphid heterochromatin is assembled and condensed without any involvement of DNA methylation
Poorly differentiated clusters (PDC) in colorectal cancer: Does their localization in tumor matter?
Poorly differentiated clusters (PDC) are aggregates of at least five neoplastic cells lacking evidence of glandular differentiation. By definition, they can be present at the invasive front (peripheral PDC or pPDC) and within the tumor stroma (central PDC or cPDC). In colorectal cancer (CRC), PDC are considered adverse prognosticators and seem to reflect epithelial mesenchymal transition (EMT). In this study, we have investigated the immuno-expression of two EMT-related proteins, E-cadherin and \u3b2-catenin, in PDC of primary CRCs and matched liver metastases. pPDC always showed nuclear \u3b2-catenin staining and diffusely reduced/absence of E-cadherin expression as opposed cPDC which showed nuclear \u3b2-catenin immunoreactivity and E-cadherin expression in about 50% of cases. In addition, the pattern of \u3b2-catenin and E-cadherin expression differed between PDC and the main tumor, and between primary CRC and liver metastasis (LM), in a percentage of cases. A discordant pattern of \u3b2-catenin and E-cadherin expression between pPDC and cPDC, between main tumor and cPDC, and between primary CRC and LM, confirms that EMT is a dynamic and reversible process in CRC. On the overall, this suggests that pPDC and cPDC are biologically different. We may advocate that PDC develop at the tumor center (cPDC) and then some of them migrate towards the tumor periphery while progressively completing EMT process (pPDC). Based on these results, PDC presence and counting may have different prognostic relevance if the assessment is done at the invasive front of the tumor or in the intratumor stroma
Novel antifouling agent zinc pyrithione: stress induction and genotoxicity on marine mussel Mytilus galloprovincialis
The anti-fouling biocide zinc pyrithione (ZnPT) was recently demonstrated to be more persistent than expected in the coastal environment, and to have a potential for bioaccumulation. We investigated the occurrence of adverse effects in the marine mussel Mytilus galloprovincialis when exposed to non-lethal concentrations of the contaminant (0.2 and 0.4 µM ZnPT), through the use of a battery of biomarkers from the molecular to the individual level. In particular, the expression of HSP27, HSP60, HSP70 and the presence of genotoxic damage were investigated in the gills and digestive gland of mussels by means of Western Blot and TUNEL procedures, respectively. In addition, a stress on stress response test was performed in order to highlight a possible general stress conditions in the exposed bivalves.A concentration of 0.2 µM ZnPT was found sufficient to trigger a marked stress response in gills and digestive gland, and a dose-dependent HSP expression was highlighted. Moreover, at the tested concentrations, ZnPT was found able to induce genotoxic effects, as demonstrated by an amplified DNA fragmentation (up to +37% of TUNEL positive cells in comparison to the control group) and by an increased frequency of apoptotic cells (up to +5%) in the tissues of the exposed mussels. In addition, the stress on stress response test demonstrated a heavily decreased tolerance to anoxic conditions in mussels exposed to the higher tested concentration of the biocide (LT50 = 5.4 days) compared to the control individuals (LT50 = 10.7 days). Multivariate analyses highlighted a strong correspondence between the observed biological effects in M. galloprovincialis, HSP over-expression and DNA damage in the gills and digestive gland, and the bioaccumulation levels of the biocide.Data presented here indicate the need for further investigations on the ZnPT effects on the key species of marine coastal communities, with the aim of obtaining the necessary information for a sound risk assessment of the impact of this new antifoulant on marine ecosystems
Biological evaluation of MR36, a novel non-polyglutamatable thymidylate synthase inhibitor that blocks cell cycle progression in melanoma cell lines.
Melanoma is one of the most common cancers, and its incidence has continued to increase over the past few decades. Chemotherapy resistance and related defects in apoptotic signaling are critical for the high mortality of melanoma. Effective drugs are lacking because apoptosis regulation in this tumor type is not well understood. The folate pathway has been considered an interesting target for anticancer therapies, and approaches targeting this pathway have recently been extended to melanoma treatment. In this study, the intracellular apoptosis signaling pathways of two melanoma cells lines (SK-MEL-2 and SK-MEL-28) were investigated after treatment with a new experimental antifolate substance (MR36) that targets thymidylate synthase. In both melanoma cell lines, apoptosis induction was triggered by a p53-independent mechanism. MR36-induced apoptosis was associated with a loss of both mitochondrial membrane potential and caspase-3 activation. Induction of cell cycle arrest by MR36 was associated with changes in the expression of key cell cycle regulators, such as p21 and cyclin D1, and the hypophosphorylation of pRb. In addition, Fas signaling was also analyzed. These findings suggest that, unlike classical antifolates, MR36 exerted an inhibitory effect on both the enzymatic function and expression of thymidylate synthase, thereby inducing apoptosis through the activation of the extrinsic and intrinsic pathways in the melanoma cell lines. MR36 showed a different mechanism of action from the known antifolates (Nolatrexed and Pemetrexed) that resulted in higher anticancer activity. Therefore, MR36 should be included as a potential new therapeutic treatment in melanoma research
Food Supplements for Skin Health: In Vitro Efficacy of a Combination of <i>Rhodiola rosea</i>, <i>Tribulus terrestris</i>, <i>Moringa oleifera</i> and <i>Undaria pinnatifida</i> on UV-Induced Damage
An increasing number of people seek treatment for aging-related conditions. Plant-derived nutraceuticals are currently of great interest in the setting of dermo-cosmetic studies for their preventive role in photoaging. We conducted an in vitro study on the possible preventive properties against photoaging of a commercially available product (Venerinase®). A mixture of Rhodiola rosea, Tribulus terrestris, Moringa oleifera, Undaria pinnatifida, folic acid and vitamin B12 (Venerinase®) was tested for its potential anti-aging effects on the skin in vitro. Conventional histology, immunofluorescence and real time PCR were employed in the research protocol. The tested product was proven to prevent UV-induced morphological changes both in keratinocytes and fibroblasts. Moreover, senescence-related and proinflammatory pathways commonly triggered by UV exposure were demonstrated to be inhibited by Venerinase® pretreatment. Our results support the potential clinical benefits of oral supplements for the treatment and/or prevention of cutaneous photodamage
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In vitro Engineering of a Skin Substitute Based on Adipose-Derived Stem Cells
In the field of wound healing, stem cell-based strategies are gaining importance for their regenerative potential. Adipose-derived stem cells (ADSCs) are a particular subset of mesenchymal stem cells present in the stromal-vascular fraction of the adipose tissue, today considered very attractive for their relative abundance and accessibility in the human body. However, ADSCs are still not routinely used in normal clinical practice. Several studies have also reported ADSC transplantation in association with biomaterials in an attempt to enhance the local retention and growth rate of the cells. The aim of our study was to evaluate the ability of ADSCs to build a dermal scaffold to be potentially used as a dermal substitute in the field of wound healing, with optimal biocompatibility and mechanical properties. ADSCs were defined as CD90-, CD73-, and CD105-positive cells. ADSCs turned out to be capable of secreting all the main components of the extracellular matrix (ECM) upon stimulation, thus efficiently producing a collagen and fibronectin-containing dermal matrix. We also checked whether the ADSC-produced dermal scaffold could be seeded with keratinocytes. The scaffolding material directly produced by ADSCs has several advantages when compared to the commercially available ones: it is easily obtained from the patients and it is 100% biocompatible and supports cell-ECM interaction. Moreover, it represents a possible powerful therapeutic tool for patients with chronic ulcers since it appears to be potentially grafted with keratinocytes layers, thus bypassing the classical two-step grafting procedure
18beta-glycyrrhetinic acid and glabridin prevent oxidative DNA fragmentation in UVB-irradiated human keratinocyte cultures.
To investigate on the possible protective activity of glycyrrhizin (GL), 18\u3b2-glycyrrhetinic acid (18\u3b2-GA) and glabridin (GLB) against UVB radiation damage in human keratinocyte cultures the following assays were performed: MTT, Comet, ROS generation and Western blot test (for the p53 activation, BCL-2 regulation and PARP cleavage). Results: 18\u3b2-GA and GLB prevented direct and indirect DNA fragmentation avoiding apoptosis activation.in human keratinocytes
Discovery Of New Sigma-2 Receptor Agonist Endowed With Antiproliferative Activity
Sigma receptors (σR) have proved to be an attractive pharmacological target for the treatment of several pathologies. In particular, σ1 ligands have been considered to play an important role in the treatment of various neurological disorders, including depression, schizophrenia, neuropathic pain, Alzheimer's and Parkinson’s disease. Moreover, it has been found that σR are involved in the modulation of cellular proliferation and cell death and σ1 antagonists and σ2 agonists may represent useful tools as anticancer and tumor imaging agents.
Recently, we reported that a properly substituted 1,3-dioxolane moiety could be employed as suitable scaffold for developing ligands for both σ1R and σ2R.1 In this work we explore a new set of structural related analogues obtained by combining different substituted spiro-heterocyclic rings with appropriate σR pharmacophoric amines. Radioligand binding assay, performed on guinea pig brain membranes, identified BS148 (1-(1,4-ditiaspiro[4.5]decan-2-ylmethyl)-4-benzylpiperidne) as the most interesting compound of the series, displaying good affinity and selectivity for σ2R .The ability of BS148 to modulate the analgesic effect of the agonist morphine was evaluated in-vivo by radiant heat tail-flick test. It exhibited anti-opioid effects on receptor-mediated analgesia, suggesting an agonistic behavior at σ1R. Moreover, BS148 demonstrated to affect the growth (MTT test) of SK-MEL-28 and SK-MEL-2 melanoma cell lines in comparison to siramesine, suggesting an agonistic behavior at σ2R.
The present work represents a new starting point for the design of potential therapeutically useful agents