Search results for: epidermal cells
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3256

Search results for: epidermal cells

2386 Targeted Photoactivatable Multiagent Nanoconjugates for Imaging and Photodynamic Therapy

Authors: Shazia Bano

Abstract:

Nanoconjugates that integrate photo-based therapeutics and diagnostics within a single platform promise great advances in revolutionizing cancer treatments. However, to achieve high therapeutic efficacy, designing functionally efficacious nanocarriers to tightly retain the drug, promoting selective drug localization and release, and the validation of the efficacy of these nanoconjugates is a great challenge. Here we have designed smart multiagent, liposome based targeted photoactivatable multiagent nanoconjugates, doped with a photoactivatable chromophore benzoporphyrin derivative (BPD) labelled with an active targeting ligand cetuximab to target the EGFR receptor (over expressed in various cancer cells) to deliver a combination of therapeutic agents. This study establishes a tunable nanoplatform for the delivery of the photoactivatable multiagent nanoconjugates for tumor-specific accumulation and targeted destruction of cancer cells in complex cancer model to enhance the therapeutic index of the administrated drugs.

Keywords: targeting, photodynamic therapy, photoactivatable, nanoconjugates

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2385 Azadirachta indica Derived Protein Encapsulated Novel Guar Gum Nanocapsules against Colon Cancer

Authors: Suman Chaudhary, Rupinder K. Kanwar, Jagat R. Kanwar

Abstract:

Azadirachta indica, also known as Neem belonging to the mahogany family is actively gaining interest in the era of modern day medicine due to its extensive applications in homeopathic medicine such as Ayurveda and Unani. More than 140 phytochemicals have been extracted from neem leaves, seed, bark and flowers for agro-medicinal applications. Among the various components, neem leaf protein (NLP) is currently the most investigated active ingredient, due to its immunomodulatory activities against tumor growth. However, these therapeutic ingredients of neem are susceptible to degradation and cannot withstand the drastic pH changes under physiological environment, and therefore, there is an urgent need of an alternative strategy such as a nano-delivery system to exploit its medicinal benefits. This study hypothesizes that guar gum (GG) derived biodegradable nano-carrier based encapsulation of NLP will improve its stability, specificity and sensitivity, thus facilitating targeted anti-cancer therapeutics. GG is a galactomannan derived from the endosperm of the guar beans seeds. Synthesis of guar nanocapsules (NCs) was performed using nanoprecipitation technique where the GG was encapsulated with NLP. Preliminary experiments conducted to characterize the NCs confirmed spherical morphology with a narrow size distribution of 30-40 nm. Differential scanning colorimetric analysis (DSC) validated the stability of these NCs even at a temperature range of 50-60°C which was well within the physiological and storage conditions. Thermogravimetric (TGA) analysis indicated high decomposition temperature of these NCs ranging upto 350°C. Additionally, Fourier Transform Infrared spectroscopy (FTIR) and the SDS-PAGE data acquired confirmed the successful encapsulation of NLP in the NCs. The anti-cancerous therapeutic property of this NC was tested on colon cancer cells (caco-2) as they are one of the most prevalent form of cancer. These NCs (both NLP loaded and void) were also tested on human intestinal epithelial cells (FHs 74) cells to evaluate their effect on normal cells. Cytotoxicity evaluation of the NCs in the cell lines confirmed that the IC50 for NLP in FHs 74 cells was ~2 fold higher than in caco-2 cells, indicating that this nanoformulation system possessed biocompatible anti-cancerous properties Immunoconfocal microscopy analysis confirmed the time dependent internalization of the NCs within 6h. Recent findings performed using Annexin V and PI staining indicated a significant increase (p ≤ 0.001) in the early and late apoptotic cell population when treated with the NCs signifying the role of NLP in inducing apoptosis in caco-2 cells. This was further validated using Western blot, Polymerase chain reaction (PCR) and Fluorescence activated cell sorter (FACS) aided protein expressional analysis which presented a downregulation of survivin, an anti-apoptotic cell marker and upregulation of Bax/Bcl-2 ratio (pro-apoptotic indicator). Further, both the NLP NC and unencapsulated NLP treatment destabilized the mitochondrial membrane potential subsequently facilitating the release of the pro-apoptotic caspase cascade initiator, cytochrome-c. Future studies will be focused towards granting specificity to these NCs towards cancer cells, along with a comprehensive analysis of the anti-cancer potential of this naturally occurring compound in different cancer and in vivo animal models, will validate the clinical application of this unprecedented protein therapeutic.

Keywords: anti-tumor, guar gum, nanocapsules, neem leaf protein

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2384 Isolation and Transplantation of Hepatocytes in an Experimental Model

Authors: Inas Raafat, Azza El Bassiouny, Waldemar L. Olszewsky, Nagui E. Mikhail, Mona Nossier, Nora E. I. El-Bassiouni, Mona Zoheiry, Houda Abou Taleb, Noha Abd El-Aal, Ali Baioumy, Shimaa Attia

Abstract:

Background: Orthotopic liver transplantation is an established treatment for patients with severe acute and end-stage chronic liver disease. The shortage of donor organs continues to be the rate-limiting factor for liver transplantation throughout the world. Hepatocyte transplantation is a promising treatment for several liver diseases and can, also, be used as a "bridge" to liver transplantation in cases of liver failure. Aim of the work: This study was designed to develop a highly efficient protocol for isolation and transplantation of hepatocytes in experimental Lewis rat model to provide satisfactory guidelines for future application on humans.Materials and Methods: Hepatocytes were isolated from the liver by double perfusion technique and bone marrow cells were isolated by centrifugation of shafts of tibia and femur of donor Lewis rats. Recipient rats were subjected to sub-lethal dose of irradiation 2 days before transplantation. In a laparotomy operation the spleen was injected by freshly isolated hepatocytes and bone marrow cells were injected intravenously. The animals were sacrificed 45 day latter and splenic sections were prepared and stained with H & E, PAS AFP and Prox1. Results: The data obtained from this study showed that the double perfusion technique is successful in separation of hepatocytes regarding cell number and viability. Also the method used for bone marrow cells separation gave excellent results regarding cell number and viability. Intrasplenic engraftment of hepatocytes and live tissue formation within the splenic tissue were found in 70% of cases. Hematoxylin and eosin stained splenic sections from 7 rats showed sheets and clusters of cells among the splenic tissues. Periodic Acid Schiff stained splenic sections from 7 rats showed clusters of hepatocytes with intensely stained pink cytoplasmic granules denoting the presence of glycogen. Splenic sections from 7 rats stained with anti-α-fetoprotein antibody showed brownish cytoplasmic staining of the hepatocytes denoting positive expression of AFP. Splenic sections from 7 rats stained with anti-Prox1 showed brownish nuclear staining of the hepatocytes denoting positive expression of Prox1 gene on these cells. Also, positive expression of Prox1 gene was detected on lymphocytes aggregations in the spleens. Conclusions: Isolation of liver cells by double perfusion technique using collagenase buffer is a reliable method that has a very satisfactory yield regarding cell number and viability. The intrasplenic route of transplantation of the freshly isolated liver cells in an immunocompromised model was found to give good results regarding cell engraftment and tissue formation. Further studies are needed to assess function of engrafted hepatocytes by measuring prothrombin time, serum albumin and bilirubin levels.

Keywords: Lewis rats, hepatocytes, BMCs, transplantation, AFP, Prox1

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2383 Luminescent and Conductive Cathode Buffer Layer for Enhanced Power Conversion Efficiency of Bulk-Heterojunction Solar Cells

Authors: Swati Bishnoi, D. Haranath, Vinay Gupta

Abstract:

In this work, we demonstrate that the power conversion efficiency (PCE) of organic solar cells (OSCs) could be improved significantly by using ZnO doped with Aluminum (Al) and Europium (Eu) as cathode buffer layer (CBL). The ZnO:Al,Eu nanoparticle layer has broadband absorption in the ultraviolet (300-400 nm) region. The Al doping contributes to the enhancement in the conductivity whereas Eu doping significantly improves emission in the visible region. Moreover, this emission overlaps with the absorption range of polymer poly [N -9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′- benzothiadiazole)] (PCDTBT) significantly and results in an enhanced absorption by the active layer and hence high photocurrent. An increase in the power conversion efficiency (PCE) of 6.8% has been obtained for ZnO: Al,Eu CBL as compared to 5.9% for pristine ZnO, in the inverted device configuration ITO/CBL/active layer/MoOx/Al. The active layer comprises of a blend of PCDTBT donor and [6-6]-phenyl C71 butyric acid methyl ester (PC71BM) acceptor. In the reference device pristine ZnO has been used as CBL, whereas in the other one ZnO:Al,Eu has been used as CBL. The role of the luminescent CBL layer is to down-shift the UV light into visible range which overlaps with the absorption of PCDTBT polymer, resulting in an energy transfer from ZnO:Al,Eu to PCDTBT polymer and the absorption by active layer is enhanced as revealed by transient spectroscopy. This enhancement resulted in an increase in the short circuit current which contributes in an increased PCE in the device employing ZnO: Al,Eu CBL. Thus, the luminescent ZnO: Al, Eu nanoparticle CBL has great potential in organic solar cells.

Keywords: cathode buffer layer, energy transfer, organic solar cell, power conversion efficiency

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2382 The Impact of Intestinal Ischaemia-Reperfusion Injury upon the Biological Function of Mesenteric Lymph

Authors: Beth Taylor, Kojima Mituaki, Atsushi Senda, Koji Morishita, Yasuhiro Otomo

Abstract:

Intestinal ischaemia-reperfusion injury drives systemic inflammation and organ failure following trauma/haemorrhagic shock (T/HS), through the release of pro-inflammatory mediators into the mesenteric lymph (ML). However, changes in the biological function of ML are not fully understood, and therefore, a specific model of intestinal ischaemia-reperfusion injury is required to obtain ML for the study of its biological function upon inflammatory cells. ML obtained from a model of intestinal ischaemia-reperfusion injury was used to assess biological function upon inflammatory cells and investigate changes in the biological function of individual ML components. An additional model was used to determine the effect of vagal nerve stimulation (VNS) upon biological function. Rat ML was obtained by mesenteric lymphatic duct cannulation before and after occlusion of the superior mesenteric artery (SMAO). ML was incubated with human polymorphonuclear neutrophils (PMNs), monocytes and lymphocytes, and the biological function of these cells was assessed. ML was then separated into supernatant, exosome and micro-vesicle components, and biological activity was compared in monocytes. A model with an additional VNS phase was developed, in which the right cervical vagal nerve was exposed and stimulated, and ML collected for comparison of biological function with the conventional model. The biological function of ML was altered by intestinal ischaemia-reperfusion injury, increasing PMN activation, monocyte activation, and lymphocyte apoptosis. Increased monocyte activation was only induced by the exosome component of ML, with no significant changes induced by the supernatant or micro-vesicle components. VNS partially attenuated monocyte activation, but no attenuation of PMN activation was observed. Intestinal ischaemia-reperfusion injury induces changes in the biological function of ML upon both innate and adaptive inflammatory cells, supporting the role of intestinal ischaemia-reperfusion injury in driving systemic inflammation following T/HS. The exosome component of ML appears to be critical to the transport of pro-inflammatory mediators in ML. VNS partially attenuates changes in innate inflammatory cell biological activity observed, presenting possibilities for future novel treatment development in multiple organ failure patients.

Keywords: exosomes, inflammation, intestinal ischaemia, mesenteric lymph, vagal stimulation

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2381 Mechanical Properties of Young and Senescence Fibroblast Cells Using Passive Microrheology

Authors: Samira Khalaji, , Fenneke Klein Jan, Kay-E. Gottschalk, Eugenia Makrantonaki, Karin Scharffetter-Kochanek

Abstract:

Biological aging is a multi-dimensional process that takes place over a whole range of scales from the nanoscopic alterations within individual cells, over transformations in tissues and organs and to changes of the whole organism. On the single cell level, aging involves mutation of genes, differences in gene expression levels as well as altered posttranslational modifications of proteins. A variety of proteins is affected, including proteins of the cell cytoskeleton and migration machinery. Previous work quantified the expression of cytoskeleton proteins on the gene and protein levels in senescent and young fibroblasts. Their results show that senescent skin fibroblasts have an upregulated expression of the intermediate filament (IF) protein vimentin in contrast to actin and tubulin, which are downregulated. IFs play an important role in providing mechanical stability of cells. However, the mechanical properties of IFs depending on cellular senescence or age of the donor has not been studied so far. Hence, we employed passive microrheology on primary human dermal fibroblasts from female donors with age of 28 years (young) and 86 years (old) as model of in vivo aging and human normal dermal fibroblast from 11-year old male with CPD 17-35 (young) and CPD 58-59 (senescence) as a model of in vitro replicative senescence. In contrast to the expectations, our primary results show no significant differences in the viscoelastic properties of fibroblasts depending on age of the donor or cellular replicative senescence.

Keywords: aging, cytoskeleton, fibroblast, mechanical properties

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2380 Check Red Blood Cells Concentrations of a Blood Sample by Using Photoconductive Antenna

Authors: Ahmed Banda, Alaa Maghrabi, Aiman Fakieh

Abstract:

Terahertz (THz) range lies in the area between 0.1 to 10 THz. The process of generating and detecting THz can be done through different techniques. One of the most familiar techniques is done through a photoconductive antenna (PCA). The process of generating THz radiation at PCA includes applying a laser pump in femtosecond and DC voltage difference. However, photocurrent is generated at PCA, which its value is affected by different parameters (e.g., dielectric properties, DC voltage difference and incident power of laser pump). THz radiation is used for biomedical applications. However, different biomedical fields need new technologies to meet patients’ needs (e.g. blood-related conditions). In this work, a novel method to check the red blood cells (RBCs) concentration of a blood sample using PCA is presented. RBCs constitute 44% of total blood volume. RBCs contain Hemoglobin that transfers oxygen from lungs to body organs. Then it returns to the lungs carrying carbon dioxide, which the body then gets rid of in the process of exhalation. The configuration has been simulated and optimized using COMSOL Multiphysics. The differentiation of RBCs concentration affects its dielectric properties (e.g., the relative permittivity of RBCs in the blood sample). However, the effects of four blood samples (with different concentrations of RBCs) on photocurrent value have been tested. Photocurrent peak value and RBCs concentration are inversely proportional to each other due to the change of dielectric properties of RBCs. It was noticed that photocurrent peak value has dropped from 162.99 nA to 108.66 nA when RBCs concentration has risen from 0% to 100% of a blood sample. The optimization of this method helps to launch new products for diagnosing blood-related conditions (e.g., anemia and leukemia). The resultant electric field from DC components can not be used to count the RBCs of the blood sample.

Keywords: biomedical applications, photoconductive antenna, photocurrent, red blood cells, THz radiation

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2379 Local Activities of the Membranes Associated with Glycosaminoglycan-Chitosan Complexes in Bone Cells

Authors: Chih-Chang Yeh, Min-Fang Yang, Hsin-I Chang

Abstract:

Chitosan is a cationic polysaccharide derived from the partial deacetylation of chitin. Hyaluronic acid (HA), chondroitin sulfate (CS) and heparin (HP) are anionic glycosaminoglycans (GCGs) which can regulate osteogenic activity. In this study, chitosan membranes were prepared by glutaraldehyde crosslinking reaction and then complexed with three different types of GCGs. 7F2 osteoblasts-like cells and macrophages Raw264.7 were used as models to study the influence of chitosan membranes on osteometabolism. Although chitosan membranes are highly hydrophilic, the membranes associated with GCG-chitosan complexes showed about 60-70% cell attachment. Furthermore, the membranes associated with HP-chitosan complexes could increase ALP activity in comparison with chitosan films only. Three types of the membranes associated with GCG-chitosan complexes could significantly inhibit LPS induced-nitric oxide expression. In addition, chitosan membranes associated with HP and HA can down-regulate tartrate-resistant acid phosphatase (TRAP) activity but not CS-chitosan complexes. Based on these results, we conclude that chitosan membranes associated with HP can increase ALP activity in osteoblasts and chitosan membranes associated with HP and HA reduce TRAP activity in osteoclasts.

Keywords: osteoblast, osteoclast, chitosan, glycosaminoglycan

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2378 Proactive SoC Balancing of Li-ion Batteries for Automotive Application

Authors: Ali Mashayekh, Mahdiye Khorasani, Thomas weyh

Abstract:

The demand for battery electric vehicles (BEV) is steadily increasing, and it can be assumed that electric mobility will dominate the market for individual transportation in the future. Regarding BEVs, the focus of state-of-the-art research and development is on vehicle batteries since their properties primarily determine vehicles' characteristic parameters, such as price, driving range, charging time, and lifetime. State-of-the-art battery packs consist of invariable configurations of battery cells, connected in series and parallel. A promising alternative is battery systems based on multilevel inverters, which can alter the configuration of the battery cells during operation via semiconductor switches. The main benefit of such topologies is that a three-phase AC voltage can be directly generated from the battery pack, and no separate power inverters are required. Therefore, modular battery systems based on different multilevel inverter topologies and reconfigurable battery systems are currently under investigation. Another advantage of the multilevel concept is that the possibility to reconfigure the battery pack allows battery cells with different states of charge (SoC) to be connected in parallel, and thus low-loss balancing can take place between such cells. In contrast, in conventional battery systems, parallel connected (hard-wired) battery cells are discharged via bleeder resistors to keep the individual SoCs of the parallel battery strands balanced, ultimately reducing the vehicle range. Different multilevel inverter topologies and reconfigurable batteries have been described in the available literature that makes the before-mentioned advantages possible. However, what has not yet been described is how an intelligent operating algorithm needs to look like to keep the SoCs of the individual battery strands of a modular battery system with integrated power electronics balanced. Therefore, this paper suggests an SoC balancing approach for Battery Modular Multilevel Management (BM3) converter systems, which can be similarly used for reconfigurable battery systems or other multilevel inverter topologies with parallel connectivity. The here suggested approach attempts to simultaneously utilize all converter modules (bypassing individual modules should be avoided) because the parallel connection of adjacent modules reduces the phase-strand's battery impedance. Furthermore, the presented approach tries to reduce the number of switching events when changing the switching state combination. Thereby, the ohmic battery losses and switching losses are kept as low as possible. Since no power is dissipated in any designated bleeder resistors and no designated active balancing circuitry is required, the suggested approach can be categorized as a proactive balancing approach. To verify the algorithm's validity, simulations are used.

Keywords: battery management system, BEV, battery modular multilevel management (BM3), SoC balancing

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2377 Histological Changes of Mice Lungs After Daily Exposure to Different Concentration of Incense Smoke

Authors: Samar Omar A. Rabah, Sahar Ragab El Hadad, Fatmah Albani

Abstract:

Since the discovery of Agarwood (Incense tree), many studies reported its characteristic effects and variable benefits, as either to produce Arabian Incense or as a traditional medicine against many diseases. Laboratory experiments were carried out on the effect of different concentrations of Incense smoke inhalation on the lung weight and tissue in female mice. This research derives its importance from the fact that Incense is heavily used in Saudi Arabia in the absence of thorough studies of its effects on health. Eighty animals are used in this study, and they are divided into four groups, each is 20 animals. Three groups are exposed to different concentrations (2, 4 and 6 gm) of Incense smoke daily for three months, and the fourth group is the control. At the end of each month, five animals from each group were dissected. Obtained data showed an increase but not significant in animal body and lung weight, this results return to natural increase as a result of normal growth of animals. Light microscope reveals some changes in the lung tissue, such as focal emphysema, rupture in the alveolar walls, hemorrhage, congestion, edema and few peri-bronchial lymphoid cells. After continuous exposure to Incense smoke focal necrosis and degradation are observed in some cells of epithelial bronchioles. Also, fibrosis of peri-bronchial, thickening in alveolar walls and aggregation of lymphoid cells are demonstrated in some lungs sections. according to the above manifestations it could be concluded that exposure to Incense smoke causes pulmonary harmful effects. Therefore, we can recommend that Incense smoke will be used only in open places to reduce its harms.

Keywords: incense smoke, lungs, histological changes of lungs, agarwood

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2376 Formulation Development and Characterization of Oligonucleotide Containing Chitosan Nanoparticles

Authors: Gyati Shilakari Asthana, Abhay Asthana

Abstract:

Purpose: The therapeutic potential of oligonucleotide (ODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study is focused to design low molecular weight chitosan nanoconstructs to meet the requirements of safe and effectual delivery of ODNs. LMW-chitosan is a biodegradable, water soluble, biocompatible polymer and is useful as a non-viral vector for gene delivery due to its better stability in water. Methods: LMW chitosan ODN nanoparticles (CHODN NPs) were formulated by self assembled method using various N/P ratios (moles ratio of amine groups of CH to phosphate moieties of ODNs; 0.5:1, 1:1, 3:1, 5:1 and 7:1) of CH to ODN. The developed CHODN NPs were evaluated with respect to gel retardation assay, particle size, zeta potential and cytotoxicity and transfection efficiency. Results: Complete complexation of CH/ODN was achieved at the charge ratio of 0.5:1 or above and CHODN NPs displayed resistance against DNase I. On increasing the N/P ratio of CH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) value increased. No significant toxicity was observed at all CH concentrations. The transfection efficiency was increased on increasing N/P ratio from 1:1 to 3:1, whereas it was decreased with further increment in N/P ratio upto 7:1. Maximum transfection of CHODN NPs with both the cell lines (Raw 267.4 cells and Hela cells) was achieved at N/P ratio of 3:1. The results suggest that transfection efficiency of CHODN NPs is dependent on N/P ratio. Conclusion: Thus the present study states that LMW chitosan nanoparticulate carriers would be acceptable choice to improve transfection efficiency in vitro as well as in vivo delivery of oligonucleotide.

Keywords: LMW-chitosan, chitosan nanoparticles, biocompatibility, cytotoxicity study, transfection efficiency, oligonucleotide

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2375 Influence of Iron Content in Carbon Nanotubes on the Intensity of Hyperthermia in the Cancer Treatment

Authors: S. Wiak, L. Szymanski, Z. Kolacinski, G. Raniszewski, L. Pietrzak, Z. Staniszewska

Abstract:

The term ‘cancer’ is given to a collection of related diseases that may affect any part of the human body. It is a pathological behaviour of cells with the potential to undergo abnormal breakdown in the processes that control cell proliferation, differentiation, and death of particular cells. Although cancer is commonly considered as modern disease, there are beliefs that drastically growing number of new cases can be linked to the extensively prolonged life expectancy and enhanced techniques for cancer diagnosis. Magnetic hyperthermia therapy is a novel approach to cancer treatment, which may greatly contribute to higher efficiency of the therapy. Employing carbon nanotubes as nanocarriers for magnetic particles, it is possible to decrease toxicity and invasiveness of the treatment by surface functionalisation. Despite appearing in recent years, magnetic particle hyperthermia has already become of the highest interest in the scientific and medical environment. The reason why hyperthermia therapy brings so much hope for future treatment of cancer lays in the effect that it produces in malignant cells. Subjecting them to thermal shock results in activation of numerous degradation processes inside and outside the cell. The heating process initiates mechanisms of DNA destruction, protein denaturation and induction of cell apoptosis, which may lead to tumour shrinkage, and in some cases, it may even cause complete disappearance of cancer. The factors which have the major impact on the final efficiency of the treatment include temperatures generated inside the tissues, time of exposure to the heating process, and the character of an individual cancer cell type. The vast majority of cancer cells is characterised by lower pH, persistent hypoxia and lack of nutrients, which can be associated to abnormal microvasculature. Since in healthy tissues we cannot observe presence of these conditions, they should not be seriously affected by elevation of the temperature. The aim of this work is to investigate the influence of iron content in iron filled Carbon Nanotubes on the desired nanoparticles for cancer therapy. In the article, the development and demonstration of the method and the model device for hyperthermic selective destruction of cancer cells are presented. This method was based on the synthesis and functionalization of carbon nanotubes serving as ferromagnetic material nanocontainers. The methodology of the production carbon- ferromagnetic nanocontainers (FNCs) includes the synthesis of carbon nanotubes, chemical, and physical characterization, increasing the content of a ferromagnetic material and biochemical functionalization involving the attachment of the key addresses. The ferromagnetic nanocontainers were synthesised in CVD and microwave plasma system. The research work has been financed from the budget of science as a research project No. PBS2/A5/31/2013.

Keywords: hyperthermia, carbon nanotubes, cancer colon cells, radio frequency field

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2374 The Stem Cell Transcription Co-factor Znf521 Sustains Mll-af9 Fusion Protein In Acute Myeloid Leukemias By Altering The Gene Expression Landscape

Authors: Emanuela Chiarella, Annamaria Aloisio, Nisticò Clelia, Maria Mesuraca

Abstract:

ZNF521 is a stem cell-associated transcription co-factor, that plays a crucial role in the homeostatic regulation of the stem cell compartment in the hematopoietic, osteo-adipogenic, and neural system. In normal hematopoiesis, primary human CD34+ hematopoietic stem cells display typically a high expression of ZNF521, while its mRNA levels rapidly decrease when these progenitors progress towards erythroid, granulocytic, or B-lymphoid differentiation. However, most acute myeloid leukemias (AMLs) and leukemia-initiating cells keep high ZNF521 expression. In particular, AMLs are often characterized by chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene, which MLL gene includes a variety of fusion oncogenes arisen from genes normally required during hematopoietic development; once they are fused, they promote epigenetic and transcription factor dysregulation. The chromosomal translocation t(9;11)(p21-22;q23), fusing the MLL gene with AF9 gene, results in a monocytic immune phenotype with an aggressive course, frequent relapses, and a short survival time. To better understand the dysfunctional transcriptional networks related to genetic aberrations, AML gene expression profile datasets were queried for ZNF521 expression and its correlations with specific gene rearrangements and mutations. The results showed that ZNF521 mRNA levels are associated with specific genetic aberrations: the highest expression levels were observed in AMLs involving t(11q23) MLL rearrangements in two distinct datasets (MILE and den Boer); elevated ZNF521 mRNA expression levels were also revealed in AMLs with t(7;12) or with internal rearrangements of chromosome 16. On the contrary, relatively low ZNF521 expression levels seemed to be associated with the t(8;21) translocation, that in turn is correlated with the AML1-ETO fusion gene or the t(15;17) translocation and in AMLs with FLT3-ITD, NPM1, or CEBPα double mutations. Invitro, we found that the enforced co-expression of ZNF521 in cord blood-derived CD34+ cells induced a significant proliferative advantage, improving MLL-AF9 effects on the induction of proliferation and the expansion of leukemic progenitor cells. Transcriptome profiling of CD34+ cells transduced with either MLL-AF9, ZNF521, or a combination of the two transgenes highlighted specific sets of up- or down-regulated genes that are involved in the leukemic phenotype, including those encoding transcription factors, epigenetic modulators, and cell cycle regulators as well as those engaged in the transport or uptake of nutrients. These data enhance the functional cooperation between ZNF521 and MA9, resulting in the development, maintenance, and clonal expansion of leukemic cells. Finally, silencing of ZNF521 in MLL-AF9-transformed primary CD34+ cells inhibited their proliferation and led to their extinction, as well as ZNF521 silencing in the MLL-AF9+ THP-1 cell line resulted in an impairment of their growth and clonogenicity. Taken together, our data highlight ZNF521 role in the control of self-renewal and in the immature compartment of malignant hematopoiesis, which, by altering the gene expression landscape, contributes to the development and/or maintenance of AML acting in concert with the MLL-AF9 fusion oncogene.

Keywords: AML, human zinc finger protein 521 (hZNF521), mixed lineage leukemia gene (MLL) AF9 (MLLT3 or LTG9), cord blood-derived hematopoietic stem cells (CB-CD34+)

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2373 Anti-Allergic Activities of Smilax Glabra Rhizome Extracts and Its Isolated Compounds

Authors: Arunporn Itharat, Kamonmas Srikwan, Srisopa Ruangnoo, Pakakrong Thongdeeying

Abstract:

Background: The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders. Objective: To investigate the in vitro anti-allergic activities of crude extracts and pure isolated flavonoid compounds from SG by determination of inhibitory effects on antigen-induced release of β-hexosaminidase from RBL-2H3 cells. Methods: The in vitro inhibitory effects of crude aqueous and organic extracts on beta-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication of possible anti-allergic activity in vivo. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts. Results: The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 μg/ml, much higher activity than that for Ketotifen (IC50 58.90 μM). The water extract had negligible activity (IC50 > 100 μg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and > 100 μg/ml, respectively. Conclusions: The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.

Keywords: Smilax glabra, anti-allergic activity, RBL-2H3 cells, flavonoid compounds

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2372 Cellular Mechanisms Involved in the Radiosensitization of Breast- and Lung Cancer Cells by Agents Targeting Microtubule Dynamics

Authors: Elsie M. Nolte, Annie M. Joubert, Roy Lakier, Maryke Etsebeth, Jolene M. Helena, Marcel Verwey, Laurence Lafanechere, Anne E. Theron

Abstract:

Treatment regimens for breast- and lung cancers may include both radiation- and chemotherapy. Ideally, a pharmaceutical agent which selectively sensitizes cancer cells to gamma (γ)-radiation would allow administration of lower doses of each modality, yielding synergistic anti-cancer benefits and lower metastasis occurrence, in addition to decreasing the side-effect profiles. A range of 2-methoxyestradiol (2-ME) analogues, namely 2-ethyl-3-O-sulphamoyl-estra-1,3,5 (10) 15-tetraene-3-ol-17one (ESE-15-one), 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16) were in silico-designed by our laboratory, with the aim of improving the parent compound’s bioavailability in vivo. The main effect of these compounds is the disruption of microtubule dynamics with a resultant mitotic accumulation and induction of programmed cell death in various cancer cell lines. This in vitro study aimed to determine the cellular responses involved in the radiation sensitization effects of these analogues at low doses in breast- and lung cancer cell lines. The oestrogen receptor positive MCF-7-, oestrogen receptor negative MDA-MB-231- and triple negative BT-20 breast cancer cell lines as well as the A549 lung cancer cell line were used. The minimal compound- and radiation doses able to induce apoptosis were determined using annexin-V and cell cycle progression markers. These doses (cell line dependent) were used to pre-sensitize the cancer cells 24 hours prior to 6 gray (Gy) radiation. Experiments were conducted on samples exposed to the individual- as well as the combination treatment conditions in order to determine whether the combination treatment yielded an additive cell death response. Morphological studies included light-, fluorescence- and transmission electron microscopy. Apoptosis induction was determined by flow cytometry employing annexin V, cell cycle analysis, B-cell lymphoma 2 (Bcl-2) signalling, as well as reactive oxygen species (ROS) production. Clonogenic studies were performed by allowing colony formation for 10 days post radiation. Deoxyribonucleic acid (DNA) damage was quantified via γ-H2AX foci and micronuclei quantification. Amplification of the p53 signalling pathway was determined by western blot. Results indicated that exposing breast- and lung cancer cells to nanomolar concentrations of these analogues 24 hours prior to γ-radiation induced more cell death than the compound- and radiation treatments alone. Hypercondensed chromatin, decreased cell density, a damaged cytoskeleton and an increase in apoptotic body formation were observed in cells exposed to the combination treatment condition. An increased number of cells present in the sub-G1 phase as well as increased annexin-V staining, elevation of ROS formation and decreased Bcl-2 signalling confirmed the additive effect of the combination treatment. In addition, colony formation decreased significantly. p53 signalling pathways were significantly amplified in cells exposed to the analogues 24 hours prior to radiation, as was the amount of DNA damage. In conclusion, our results indicated that pre-treatment of breast- and lung cancer cells with low doses of 2-ME analogues sensitized breast- and lung cancer cells to γ-radiation and induced apoptosis more so than the individual treatments alone. Future studies will focus on the effect of the combination treatment on non-malignant cellular counterparts.

Keywords: cancer, microtubule dynamics, radiation therapy, radiosensitization

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2371 Characterization of Calcium-Signalling Mediated by Human GPR55 Expressed in HEK293 Cells

Authors: Yousuf M. Al Suleimani, Robin Hiley

Abstract:

The endogenous phospholipid lysophosphatidylinositol (LPI) was recently identified as a novel ligand for the G protein-coupled receptor 55 (GPR55) and an inducer of intracellular Ca2+ [Ca2+]i release. This study attempts to characterize Ca2+ signals provoked by LPI in HEK293 cells engineered to stably express human GPR55 and to test cannabinoid ligand activity at GPR55. The study shows that treatment with LPI stimulates a sustained, oscillatory Ca2+ release. The response is characterized by an initial rapid rise, which is mediated by the Gαq-PLC-IP3 pathway, and this is followed by prolonged oscillations that require RhoA activation. Ca2+ oscillations are initiated by intracellular mechanisms and extracellular Ca2+ is only required to replenish Ca2+ lost from the cytoplasm. Analysis of cannabinoid ligand activity at GPR55 revealed no clear effect of the endocannabinoid anandamide, however, rimonabant and the CB1 receptor antagonist AM251 evoked GPR55-mediated [Ca2+]i. Thus, LPI is likely to be a key plasma membrane mediator of signaling events and changes in gene expression through GPR55 activation.

Keywords: lysophosphatidylinositol, calcium, GPR55, cannabinoid

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2370 The Improved Therapeutic Effect of Trans-Cinnamaldehyde on Adipose-Derived Stem Cells without Chemical Induction

Authors: Karthyayani Rajamani, Yi-Chun Lin, Tung-Chou Wen, Jeanne Hsieh, Yi-Maun Subeq, Jen-Wei Liu, Po-Cheng Lin, Horng-Jyh Harn, Shinn-Zong Lin, Tzyy-Wen Chiou

Abstract:

Assuring cell quality is an essential parameter for the success of stem cell therapy, utilization of various components to improve this potential has been the primary goal of stem cell research. The aim of this study was not only to demonstrate the capacity of trans-cinnamaldehyde (TC) to reverse stress-induced senescence but also improve the therapeutic abilities of stem cells. Because of the availability and the promising application potential in regenerative medicine, adipose-derived stem cells (ADSCs) were chosen for the study. We found that H2O2 treatment resulted in the expression of senescence characteristics in the ADSCs, including decreased proliferation rate, increased senescence-associated- β-galactosidase (SA-β-gal) activity, decreased SIRT1 (silent mating type information regulation 2 homologs) expression and decreased telomerase activity. However, TC treatment was sufficient to rescue or reduce the effects of H2O2 induction, ultimately leading to an increased proliferation rate, a decrease in the percentage of SA-β-gal positive cells, upregulation of SIRT1 expression, and increased telomerase activity of the senescent ADSCs at the cellular level. Further recently it was observed that the ADSCs were treated with TC without induction of senescence, all the before said positives were observed. Moreover, a chemically induced liver fibrosis animal model was used to evaluate the functionality of these rescued cells in vivo. Liver dysfunction was established by injecting 200 mg/kg thioacetamide (TAA) intraperitoneally into Wistar rats every third day for 60 days. The experimental rats were separated into groups; normal group (rats without TAA induction), sham group (without ADSC transplantation), positive control group (transplanted with normal ADSCs); H2O2 group (transplanted with H2O2 -induced senescent ADSCs), H2O2+TC group (transplanted with ADSCs pretreated with H2O2 and then further treated with TC) and TC group (ADSC treated with TC without H2O2 treatment). In the transplantation group, 1 × 106 human ADSCs were introduced into each rat via direct liver injection. Based on the biochemical analysis and immunohistochemical staining results, it was determined that the therapeutic effects on liver fibrosis by the induced senescent ADSCs (H2O2 group) were not as significant as those exerted by the normal ADSCs (the positive control group). However, the H2O2+TC group showed significant reversal of liver damage when compared to the H2O2 group 1 week post-transplantation. Further ADSCs without H2O2 treatment but with just TC treatment performed much better than all the groups. These data confirmed that the TC treatment had the potential to improve the therapeutic effect of ADSCs. It is therefore suggested that TC has potential applications in maintaining stem cell quality and could possibly aid in the treatment of senescence-related disorders.

Keywords: senescence, SIRT1, adipose derived stem cells, liver fibrosis

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2369 Cytotoxicity and Androgenic Potential of Antifungal Drug Substances on MDA-KB2 Cells

Authors: Benchouala Amira, Bojic Clement, Poupin Pascal, Cossu Leguille-carole

Abstract:

The objective of this study is to evaluate in vitro the cytotoxic and androgenic potential of several antifungal molecules (amphotericin B, econazole, ketoconazole and miconazole) on MDA-Kb2 cell lines. This biological model is an effective tool for the detection of endocrine disruptors because it responds well to the main agonist of the androgen receptor (testosterone) and also to an antagonist: flutamide. The cytotoxicity of each chemical compound tested was measured using an MTT assay (tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) which measures the activity of the reductase function of mitochondrial succinate dehydrogenase enzymes of cultured cells. This complementary cytotoxicity test is essential to ensure that the effects of reduction in luminescence intensity observed during androgenic tests are only attributable to the anti-androgenic action of the compounds tested and not to their possible cytotoxic properties. Tests of the androgenic activity of antifungals show that these compounds do not have the capacity to induce transcription of the luciferase gene. These compounds do not exert an androgenic effect on MDA-Kb2 cells in culture for the environmental concentrations tested. The addition of flutamide for the same tested concentrations of antifungal molecules reduces the luminescence induced by amphotericin B, econazole and miconazole, which is explained by a strong interaction of these molecules with flutamide which may have a greater toxic effect than when tested alone. The cytotoxicity test shows that econazole and ketoconazole can cause cell death at certain concentrations tested. This cell mortality is perhaps induced by a direct or indirect action on deoxyribonucleic acid (DNA), ribonucleic acid (RNA) or proteins necessary for cell division.

Keywords: cytotoxicity, androgenic potential, antifungals, MDA-Kb2

Procedia PDF Downloads 51
2368 Food Supplements and Natural Products to Slow Down Biological Aging

Authors: Coppa Federica, Iannello Giulia, Pennisi Stefania, Giuffrida Graziella, Lo Faro Riccardo, Cartelli Simone, Ferruggia Greta, Brundo Maria Violetta

Abstract:

In recent years, a new field of basic research has emerged: the biology and physiology of extracellular vesicles and their application in diagnostics and therapy. In particular, exosomes attract the scientific community as nanovesicles of endosomal origin, which can be secreted by a variety of cells and are found in all biological fluids. Exosomes have recently gained attention also in the cosmetic field: in fact, they are used in creams, serums and masks for topical use, proving to have a series of therapeutic and anti-aging benefits. To date, the oral administration of exosomes is the subject of attention because it represents a non-invasive and efficient method for delivering bioactive molecules into the intestine. We decided to focus our research on the creation of a food supplement that contains various bioactive factors, vitamins, and a new technology called AMPLEX PLUS, containing a mixture of 20 different biologically active factors (GF20) and exosomes isolated and purified from bovine colostrum. We have demonstrated in vitro that this new supplement acts on telomerase, slowing down cell aging. Amplex plus increased the proliferation rate of cells and the addition of it reduced the rate of telomere shortening. Under oxidative stress conditions (H2O2 – induced), the TSR increased; however, treatment with colostrum appeared to attenuate this increase. In particular, after 2 weeks of treatment, AMPLEX plus increased the proliferation rate of cells and exerted a protective effect on telomere length erosion, reducing the rate of its shortening.

Keywords: AMPLEX PLUS, colostrum, exosomes, telomerase

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2367 Triple Immunotherapy to Overcome Immune Evasion by Tumors in a Melanoma Mouse Model

Authors: Mary-Ann N. Jallad, Dalal F. Jaber, Alexander M. Abdelnoor

Abstract:

Introduction: Current evidence confirms that both innate and adaptive immune systems are capable of recognizing and abolishing malignant cells. The emergence of cancerous tumors in patients is, therefore, an indication that certain cancer cells can resist elimination by the immune system through a process known as “immune evasion”. In fact, cancer cells often exploit regulatory mechanisms to escape immunity. Such mechanisms normally exist to control the immune responses and prohibit exaggerated or autoimmune reactions. Recently, immunotherapies have shown promising yet limited results. Therefore this study investigates several immunotherapeutic combinations and devises a triple immunotherapy which harnesses the innate and acquired immune responses towards the annihilation of malignant cells through overcoming their ability of immune evasion, consequently hampering malignant progression and eliminating established tumors. The aims of the study are to rule out acute/chronic toxic effects of the proposed treatment combinations, to assess the effect of these combinations on tumor growth and survival rates, and to investigate potential mechanisms underlying the phenotypic results through analyzing serum levels of anti-tumor cytokines, angiogenic factors and tumor progression indicator, and the tumor-infiltrating immune-cells populations. Methodology: For toxicity analysis, cancer-free C57BL/6 mice are randomized into 9 groups: Group 1 untreated, group 2 treated with sterile saline (solvent of used treatments), group 3 treated with Monophosphoryl-lipid-A, group 4 with anti-CTLA4-antibodies, group 5 with 1-Methyl-Tryptophan (Indolamine-Dioxygenase-1 inhibitor), group 6 with both MPLA and anti-CTLA4-antibodies, group 7 with both MPLA and 1-MT, group 8 with both anti-CTLA4-antibodies and 1-MT, and group 9 with all three: MPLA, anti-CTLA4-antibodies and 1-MT. Mice are monitored throughout the treatment period and for three following months. At that point, histological sections from their main organs are assessed. For tumor progression and survival analysis, a murine melanoma model is generated by injecting analogous mice with B16F10 melanoma cells. These mice are segregated into the listed nine groups. Their tumor size and survival are monitored. For a depiction of underlying mechanisms, melanoma-bearing mice from each group are sacrificed at several time-points. Sera are tested to assess the levels of Interleukin-12 (IL-12), Vascular-Endothelial-Growth Factor (VEGF), and S100B. Furthermore, tumors are excised for analysis of infiltrated immune cell populations including T-cells, macrophages, natural killer cells and immune-regulatory cells. Results: Toxicity analysis shows that all treated groups present no signs of neither acute nor chronic toxicity. Their appearance and weights were comparable to those of control groups throughout the treatment period and for the following 3 months. Moreover, histological sections from their hearts, kidneys, lungs, and livers were normal. Work is ongoing for completion of the remaining study aims. Conclusion: Toxicity was the major concern for the success of the proposed comprehensive combinational therapy. Data generated so far ruled out any acute or chronic toxic effects. Consequently, ongoing work is quite promising and may significantly contribute to the development of more effective immunotherapeutic strategies for the treatment of cancer patients.

Keywords: cancer immunotherapy, check-point blockade, combination therapy, melanoma

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2366 Land Use Change Modeling Using Cellular Automata, Case Study: Karawang City, West Java Province, Indonesia

Authors: Bagus Indrawan Hardi

Abstract:

Cellular Automata are widely used in land use modeling, it has been proven powerful to simulate land use change for small scale in many large cities in the world. In this paper, we try to implement CA for land use modeling in unique city in Indonesia, Karawang. Instead the complex numerical implementation, CA are simple, and it is accurate and also highly dependable on the on the rules (rule based). The most important to do in CA is how we form and calculate the neighborhood effect. The neighborhood effect represents the environment and relationship situation between the occupied cell and others. We adopted 196 cells of circular neighborhood with 8 cells of radius. For the results, CA works well in this study, we exhibit several analyzed and proceed of zoomed part in Karawang region. The rule set can handle the complexity in land use modeling. However, we cannot strictly believe of the result, many non-technical parameters, such as politics, natural disaster activities, etc. may change the results dramatically.

Keywords: cellular automata (CA), land use change, spatial dynamics, urban sprawl

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2365 Lanthanum Strontium Titanate Based Anode Materials for Intermediate Temperature Solid Oxide Fuel Cells

Authors: A. Saurabh Singh, B. Raghvendra, C. Prabhakar Singh

Abstract:

Solid Oxide Fuel Cells (SOFCs) are one of the most attractive electrochemical energy conversion systems, as these devices present a clean energy production, thus promising high efficiencies and low environmental impact. The electrodes are the main components that decisively control the performance of a SOFC. Conventional, anode materials (like Ni-YSZ) are operates at very high temperature. Therefore, cost-effective materials which operate at relatively lower temperatures are still required. In present study, we have synthesized La doped Strontium Titanate via solid state reaction route. The structural, microstructural and density of the pellet have been investigated employing XRD, SEM and Archimedes Principle, respectively. The electrical conductivity of the systems has been determined by impedance spectroscopy techniques. The electrical conductivity of the Lanthanum Strontium Titanate (LST) has been found to be higher than the composite Ni-YSZ system at 700 °C.

Keywords: IT-SOFC, LST, Lanthanum Strontium Titanate, electrical conductivity

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2364 The Efficacy of Thymbra spicata Ethanolic Extract and its Main Component Carvacrol on In vitro Model of Metabolically-Associated Dysfunctions

Authors: Farah Diab, Mohamad Khalil, Francesca Storace, Francesca Baldini, Piero Portincasaa, Giulio Lupidi, Laura Vergani

Abstract:

Thymbra spicata is a thyme-like plant belonging to the Lamiaceae family that shows a global distribution, especially in the eastern Mediterranean region. Leaves of T. spicata contain large amounts of phenols such as phenolic acids (rosmarinic acid), phenolic monoterpenes (carvacrol), and flavonoids. In Lebanon, T. spicata is currently used as a culinary herb in salad and infusion, as well as for traditional medicinal purposes. Carvacrol (5-isopropyl-2-methyl phenol), the most abundant polyphenol in the organic extract and essential oils, has a great array of pharmacological properties. In fact, carvacrol is largely employed as a food additive and neutraceutical agent. Our aim is to investigate the beneficial effects of T. spicata ethanolic extract (TE) and its main component, carvacrol, using in vitro models of hepatic steatosis and endothelial dysfunction. As a further point, we focused on investigating if and how the binding of carvacrol to albumin, the physiological transporter for drugs in the blood, might be altered by the presence of high levels of fatty acids (FAs), thus impairing the carvacrol bio-distribution in vivo. For that reason, hepatic FaO cells treated with exogenous FAs such as oleate and palmitate mimic hepatosteatosis; endothelial HECV cells exposed to hydrogen peroxide are a model of endothelial dysfunction. In these models, we measured lipid accumulation, free radical production, lipoperoxidation, and nitric oxide release before and after treatment with carvacrol. The carvacrol binding to albumin with/without high levels of long-chain FAs was assessed by absorption and emission spectroscopies. Our findings show that both TE and carvacrol (i) counteracted lipid accumulation in hepatocytes by decreasing the intracellular and extracellular lipid contents in steatotic FaO cells; (ii) decreased oxidative stress in endothelial cells by significantly reducing lipoperoxidation and free radical production, as well as, attenuating the nitric oxide release; (ii) high levels of circulating FAs reduced the binding of carvacrol to albumin. The beneficial effects of TE and carvacrol on both hepatic and endothelial cells point to a nutraceutical potential. However, high levels of circulating FAs, such as those occurring in metabolic disorders, might hinder the carvacrol transport, bio-distribution, and pharmacodynamics.

Keywords: carvacrol, endothelial dysfunction, fatty acids, non-alcoholic fatty liver diseases, serum albumin

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2363 Forced Swim Stress Does Not Induce Structural Chromosomal Aberrations in Rat Bone Marrow

Authors: Mohammad Y. Alfaifi

Abstract:

Anything that poses a challenge or a threat to our well-being is a stress. Understanding the genetic material and cellular response of rats threatened with Repeated swimming stress provides insights that can influence human health. The aim of the present study was to assess the genetical damage and cytological changes caused by exposure of the test organism (Rattus rattus) to forced swimming stress. For this purpose, animals have been submerged in water path 15 minutes daily for 2 weeks. Following that, we performed a micronuclei (MN) test using MNNCE (Micronucleated normocromatic erythrocytes) and MNPCE (Micronucleated polychromatic erythrocytes), NDI (Nuclear division index) and cytological parameters using NDCI (nuclear division cytotoxicity index), necrotic and apoptotic cells in rat's bone marrow samples. Results showed that there was a slightly but not significant increase in the frequency of micronucleated as well as in cytological parameters in bone marrow cells.

Keywords: submergence stress, micronucleus, NDI, NDCI, toxicity, chromosomal aberrations

Procedia PDF Downloads 396
2362 Control of Lymphatic Remodelling by miR-132

Authors: Valeria Arcucci, Musarat Ishaq, Steven A. Stacker, Greg J. Goodall, Marc G. Achen

Abstract:

Metastasis is the lethal aspect of cancer for most patients. Remodelling of lymphatic vessels associated with a tumour is a key initial step in metastasis because it facilitates the entry of cancer cells into the lymphatic vasculature and their spread to lymph nodes and distant organs. Although it is clear that vascular endothelial growth factors (VEGFs), such as VEGF-C and VEGF-D, are key drivers of lymphatic remodelling, the means by which many signaling pathways in endothelial cells are coordinately regulated to drive growth and remodelling of lymphatics in cancer is not understood. We seek to understand the broader molecular mechanisms that control cancer metastasis, and are focusing on microRNAs, which coordinately regulate signaling pathways involved in complex biological responses in health and disease. Here, using small RNA sequencing, we found that a specific microRNA, miR-132, is upregulated in expression in lymphatic endothelial cells (LECs) in response to the lymphangiogenic growth factors. Interestingly, ectopic expression of miR-132 in LECs in vitro stimulated proliferation and tube formation of these cells. Moreover, miR-132 is expressed in lymphatic vessels of a subset of human breast tumours which were previously found to express high levels of VEGF-D by immunohistochemical analysis on tumour tissue microarrays. In order to dissect the complexity of regulation by miR-132 in lymphatic biology, we performed Argonaute HITS-CLIP, which led us to identify the miR-132-mRNA interactome in LECs. We found that this microRNA in LECs is involved in the control of many different pathways mainly involved in cell proliferation and regulation of the extracellular matrix and cell-cell junctions. We are now exploring the functional significance of miR-132 targets in the biology of LECs using biochemical techniques, functional in vitro cell assays and in vivo lymphangiogenesis assays. This project will ultimately define the molecular regulation of lymphatic remodelling by miR-132, and thereby identify potential therapeutic targets for drugs designed to restrict the growth and remodelling of tumour lymphatics resulting in metastatic spread.

Keywords: argonaute HITS-CLIP, cancer, lymphatic remodelling, miR-132, VEGF

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2361 COX-2 Inhibitor NS398 Counteracts Chemoresistance to Temozolomide in T98G Glioblastoma Cell Line

Authors: Francesca Lombardi, Francesca Rosaria Augello, Benedetta Cinque, Maria Grazia Cifone, Paola Palumbo

Abstract:

Glioblastoma multiforme (GBM) is a high-grade primary brain tumor refractory to current forms of treatment. The survival benefits of patients with GBM remain unsatisfactory due to the intrinsic or acquired resistance to temozolomide (TMZ), an alkylating agent, used as the first-line chemotherapeutic drug to treat GBM patients. Its cytotoxic effect is visualized by the induction of O6-methylguanine (O6MeG) within DNA. Cyclooxygenase-2 (COX-2), an inflammation-associated enzyme, has been implicated in tumorigenesis and progression of GBM, its inhibition shows anticancer activities. In the present study, it was verified if the combination of a COX-2 selective inhibitor, NS398, with TMZ could counteract the TMZ resistance. In particular, the effect of NS398 mixed with TMZ was investigated in the GBM TMZ-resistant cell line, T98G. Cells were pretreated with NS398 (100µM, 24 hours) and then exposed to TMZ alone (200µM), NS398 alone, or both for 72 hours, after which cell growth rate and cycle phases, as well as apoptosis level, were evaluated. Coadministration of NS398 and TMZ caused a significant decrease in cell growth and a progressive increase of dead cells detected by trypan blue staining. Moreover, a significant level of apoptotic cell percentage and alteration of cell cycle phases were observed in T98G treated with TMZ-NS398 combination when compared to untreated cells or TMZ-treated cells. TMZ-resistant tumors, as GBM, express elevated levels of DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT). The mixture drastically reduced MGMT expression in the TMZ-resistant cell line T98G, known to express high levels of MGMT basically. Moreover, while TMZ alone did not influence the COX-2 protein expression, the combination successfully reduced it. In conclusion, these results demonstrated that NS398 enhanced the efficacy of TMZ through cell number reduction, apoptosis induction, and decreased MGMT levels, suggesting the ability of drug combination to reduce the chemoresistance. This drug combination deserves attention and could be considered as a promising therapeutic strategy for GBM patients.

Keywords: COX-2, COX-2 inhibitor, glioblastoma, NS398, T98G, temozolomide

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2360 Inhibition of Influenza Replication through the Restrictive Factors Modulation by CCR5 and CXCR4 Receptor Ligands

Authors: Thauane Silva, Gabrielle do Vale, Andre Ferreira, Marilda Siqueira, Thiago Moreno L. Souza, Milene D. Miranda

Abstract:

The exposure of A(H1N1)pdm09-infected epithelial cells (HeLa) to HIV-1 viral particles, or its gp120, enhanced interferon-induced transmembrane protein (IFITM3) content, a viral restriction factor (RF), resulting in a decrease in influenza replication. The gp120 binds to CCR5 (R5) or CXCR4 (X4) cell receptors during HIV-1 infection. Then, it is possible that the endogenous ligands of these receptors also modulate the expression of IFITM3 and other cellular factors that restrict influenza virus replication. Thus, the aim of this study is to analyze the role of cellular receptors R5 and X4 in modulating RFs in order to inhibit the replication of the influenza virus. A549 cells were treated with 2x effective dose (ED50) of endogenous R5 or X4 receptor agonists, CCL3 (20 ng/ml), CCL4 (10 ng/ml), CCL5 (10 ng/ml) and CXCL12 (100 ng/mL) or exogenous agonists, gp120 Bal-R5, gp120 IIIB-X4 and its mutants (5 µg/mL). The interferon α (10 ng/mL) and oseltamivir (60 nM) were used as a control. After 24 h post agonists exposure, the cells were infected with virus influenza A(H3N2) at 2 MOI (multiplicity of infection) for 1 h. Then, 24 h post infection, the supernatant was harvested and, the viral titre was evaluated by qRT-PCR. To evaluate IFITM3 and SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) protein levels, A549 were exposed to agonists for 24 h, and the monolayer was lysed with Laemmli buffer for western blot (WB) assay or fixed for indirect immunofluorescence (IFI) assay. In addition to this, we analyzed other RFs modulation in A549, after 24 h post agonists exposure by customized RT² Profiler Polymerase Chain Reaction Array. We also performed a functional assay in which SAMHD1-knocked-down, by single-stranded RNA (siRNA), A549 cells were infected with A(H3N2). In addition, the cells were treated with guanosine to assess the regulatory role of dNTPs by SAMHD1. We found that R5 and X4 agonists inhibited influenza replication in 54 ± 9%. We observed a four-fold increase in SAMHD1 transcripts by RFs mRNA quantification panel. After 24 h post agonists exposure, we did not observe an increase in IFITM3 protein levels through WB or IFI assays, but we observed an upregulation up to three-fold in the protein content of SAMHD1, in A549 exposed to agonists. Besides this, influenza replication enhanced in 20% in cell cultures that SAMDH1 was knockdown. Guanosine treatment in cells exposed to R5 ligands further inhibited influenza virus replication, suggesting that the inhibitory mechanism may involve the activation of the SAMHD1 deoxynucleotide triphosphohydrolase activity. Thus, our data show for the first time a direct relationship of SAMHD1 and inhibition of influenza replication, and provides perspectives for new studies on the signaling modulation, through cellular receptors, to induce proteins of great importance in the control of relevant infections for public health.

Keywords: chemokine receptors, gp120, influenza, virus restriction factors

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2359 Epigenomic Analysis of Lgr5+ Stem Cells in Gastrointestinal Tract

Authors: Hyo-Min Kim, Seokjin Ham, Mi-Joung Yoo, Minseon Kim, Tae-Young Roh

Abstract:

The gastrointestinal (GI) tract of most animals, including murine, is highly compartmentalized epithelia which also provide distinct different functions of its own tissue. Nevertheless, these epithelia share certain characteristics that enhance immune responses to infections and maintain the barrier function of the intestine. GI tract epithelia also undergo regeneration not only in homeostatic conditions but also in a response to the damage. A full turnover of the murine gastrointestinal epithelium occurs every 4-5 day, a process that is regulated and maintained by a minor population of Lgr5+ adult stem cell that commonly conserved in the bottom of crypts through GI tract. Maintenance of the stem cell is somehow regulated by epigenetic factors according to recent studies. Chromatin vacancy, remodelers, histone variants and histone modifiers could affect adult stem cell fate. In this study, Lgr5-EGFP reporter mouse was used to take advantage of exploring the epigenetic dynamics among Lgr5 positive mutual stem cell in GI tract. Cells were isolated by fluorescence-activated cell sorting (FACS), gene expression levels, chromatin accessibility changes and histone modifications were analyzed. Some notable chromatin structural related epigenetic variants were detected. To identify the overall cell-cell interaction inside the stem cell niche, an extensive genome-wide analysis should be also followed. According to the results, nevertheless, we expected a broader understanding of cellular niche maintaining stem cells and epigenetic barriers through conserved stem cell in GI tract. We expect that our study could provide more evidence of adult stem cell plasticity and more chances to understand each stem cell that takes parts in certain organs.

Keywords: adult stem cell, epigenetics, LGR5 stem cell, gastrointestinal tract

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2358 Survival of Micro-Encapsulated Probiotic Lactic Acid Bacteria in Mutton Nuggets and Their Assessments in Simulated Gastro-Intestinal Conditions

Authors: Rehana Akhter, Sajad A. Rather, F. A. Masoodi, Adil Gani, S. M. Wani

Abstract:

During recent years probiotic food products receive market interest as health-promoting, functional foods, which are believed to contribute health benefits. In order to deliver the health benefits by probiotic bacteria, it has been recommended that they must be present at a minimum level of 106 CFU/g to 107 CFU/g at point of delivery or be eaten in sufficient amounts to yield a daily intake of 108 CFU. However a major challenge in relation to the application of probiotic cultures in food matrix is the maintenance of viability during processing which might lead to important losses in viability as probiotic cultures are very often thermally labile and sensitive to acidity, oxygen or other food constituents for example, salts. In this study Lactobacillus plantarum and Lactobacillus casei were encapsulated in calcium alginate beads with the objective of enhancing their survivability and preventing exposure to the adverse conditions of the gastrointestinal tract and where then inoculated in mutton nuggets. Micro encapsulated Lactobacillus plantarum and Lactobacillus casei were resistant to simulated gastric conditions (pH 2, 2h) and bile solution (3%, 2 h) resulting in significantly (p ≤ 0.05) improved survivability when compared with free cell counterparts. A high encapsulation yield was found due to the encapsulation procedure. After incubation at low pH-values, micro encapsulation yielded higher survival rates compared to non-encapsulated probiotic cells. The viable cell numbers of encapsulated Lactobacillus plantarum and Lactobacillus casei were 107-108 CFU/g higher compared to free cells after 90 min incubation at pH 2.5. The viable encapsulated cells were inoculated into mutton nuggets at the rate of 108 to 1010 CFU/g. The micro encapsulated Lactobacillus plantarum and Lactobacillus casei achieved higher survival counts (105-107 CFU/g) than the free cell counterparts (102-104 CFU/g). Thus micro encapsulation offers an effective means of delivery of viable probiotic bacterial cells to the colon and maintaining their survival during simulated gastric, intestinal juice and processing conditions during nugget preparation.

Keywords: survival, Lactobacillus plantarum, Lactobacillus casei, micro-encapsulation, nugget

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2357 Anti-Prostate Cancer Effect of GV-1001, a Novel Gonadotropin-Releasing Hormone Receptor Ligand

Authors: Ji Won Kim, Moo Yeol Lee, Keon Wook Kang

Abstract:

GV-1001, 16 amino acid fragment of human telomerase reverse transcriptase catalytic subunit (hTERT), has been developed as an injectable cancer vaccine for many types of solid tumors showing high-level of telomerase activity. In the present study, we evaluated the anti-cancer effect of GV-1001 on androgen-receptor-positive prostate cancer. Two signaling pathways, Gs-adenylate cyclase-cAMP and Gq-IP3-Ca2+ pathways play a central role in GnRH receptor (GnRHR)-mediated activities. We found that leuprolide acetate (LA) mainly acted on Gq-mediated Ca2+ signaling, while GV-1001 preferentially acted on cAMP signaling; and both the effects were counteracted by cetrorelix, a GnRHR antagonist. We further tested whether GV-1001 affects tumor growth of human prostate cancer cells in vivo. Prostate tumor xenografts were established using LNCap, androgen receptor-positive prostate cancer cells, and the nude mice bearing tumors were subcutaneously injected with GV-1001 (0.01, 0.1, 1, 10 microg/kg/day) and LA (0.01 microg/kg/day) for 2 weeks. GV-1001 (1 and 10 microg/kg/day) significantly inhibited tumor growth of LNCap xenografts. Interestingly, mRNA expression of MMP2 and MMP9 was significantly suppressed by GV-1001 injection, but not by LA administration. Boyden chamber assay revealed that GV-1001 potently inhibited cell migration of LNCap. Our finding suggests that GV-1001 as a novel GnRHR ligand, has anti-proliferative and anti-migratory effects on androgen receptor-positive prostate cancer cells.

Keywords: GV-1001, GnRH, hTERT, prostate cancer

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