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Sample records for asialoglycoproteins

  1. Asialoglycoprotein receptor targeted imaging using Tc-99m galactosylated chitosan

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    Kim, E. M.; Jeong, H. J.; Kim, B. C.; Kim, C. K [Wonkang University College of Medicine, Iksan (Korea, Republic of)

    2004-07-01

    The asialoglycoprotein receptor (ASGP-R) is expressed on liver hepatocytes. Chitosan conjugates of galactose have shown to be specifically taken up by liver parenchymal cells via ASGP-R. In this study, Tc-99m hydrazino nicotinamide (HYNIC)-galactosylated chitosan (HYNIC-GC) was synthesized and evaluated as a targeted agent for the imaging of hepatocytes. GC was obtained after coupling of lactobionic acid as the galactose moiety and coupled with HYNIC. HYNIC-GC was radiolabeled with Tc-99m using stannous chloride and tricine as reducing agent and coligand respectively. Hepatic uptake property of Tc-99m HYNIC-GC was studied in female Balb/C mouse. Tc-99m HYNIC--GC and Tc-99m HYNIC-Chitosan as a control were intravenously injected into mice. Receptor binding was identified by coinjection with 50 mM and 80mM free galactose respectively. Biodistribution was determined at three different time points. The level of galactose substitution was 7.6%. Labeling efficiency was >90% both in vitro and serum up to 24 h. Tc-99m HYNIC-GC injected via tail vein of mice showed high selectivity of liver. On the other hands, Tc-99m HC without galactose group showed low uptake (Fig. 1A, 1B). Hepatic uptake of Tc-99m HYNIC-GC was dramatically blocked by 50 mM and 80 mM free galactose coinjection (Fig. 1C, 1D). The liver accumulated about 14 percent injected dose per gram (%ID/g) up to 120 min after injection. Tc-99m HYNIC-GC showed specific and rapid targeting to liver. It is a promising specific radiopharmaceutical with potential applications in the imaging of liver parenchymal cells.

  2. Characterization of the interaction between urinary urokinase and the asialoglycoprotein receptor of liver cells

    NARCIS (Netherlands)

    Rijken, D.C.; Kaaden, M.E. van der; Groeneveld, E.; Barrett-Bergshoeff, M.M.; Thjc, B. van; Kuiper, J.

    1996-01-01

    Urokinase-type plasminogen activator (u-PA) is rapidly cleared from the circulation with a half-life of a few minutes. We have previously shown that non-glycosylated recombinant u-PA is recognized by LRP, whereas urinary u-PA is recognized by the asialoglycoprotein receptor (ASGPr) on liver

  3. Effects of chronic ethanol administration on total asialoglycoprotein receptor content in isolated rat hepatocytes

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    Casey, C.A.; Kragskow, S.L.; Sorrell, M.F.; Tuma, D.J.

    1987-05-01

    The authors have previously shown that chronic ethanol administration impairs receptor-mediated endocytosis of asialoorosomucoid (ASOR) in hepatocytes. Decreased surface binding, degradation, and internalization of /sup 125/I-ASOR, along with decreased receptor recycling, was shown in hepatocytes isolated from rats fed a liquid ethanol diet for 5-7 weeks as compared to values obtained from hepatocytes isolated from chow-fed and pair-fed control rats. The present study was undertaken to determine the effect of chronic ethanol feeding on total asialoglycoprotein receptor number and on the distribution of intracellular versus surface membrane receptor content of the hepatocytes. Chronic ethanol administration produced a significant decrease (30-50%, p<.01) in the total number of binding sites/10/sup 6/ cells, as determined by /sup 125/I-ASOR binding to cells which has been permeabilized with .055% digitonin, when compared to controls. The distribution of surface membrane/intracellular binding site number was, however, unchanged by chronic ethanol feeding. The decrease in both total and surface binding of /sup 125/I-ASOR to cells from ethanol-fed rats was confirmed using anti-rat antibody binding to intact and permeabilized cells. These results indicate that both surface and total asialoglycoprotein receptor content is decreased by chronic ethanol feeding.

  4. Understanding the Selectivity Mechanism of the Human Asialoglycoprotein Receptor (ASGP-R) toward Gal- and Man- type Ligands for Predicting Interactions with Exogenous Sugars

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    Emo Chiellini; Federica Chiellini; Anna Maria Bianucci; Laura Murgia; Ilaria Massarelli

    2007-01-01

    A practical approach for addressing the computer simulation of protein-carbohydrate interactions is described here. An articulated computational protocol was set up and validated by checking its ability to predict experimental data, available in the literature, and concerning the selectivity shown by the Carbohydrate Recognition Domain (CRD) of the human asialoglycoprotein receptor (ASGP-R) toward Gal-type ligands. Some required features responsible for the interactions were identified. Subse...

  5. Electrochemical evidence for asialoglycoprotein receptor – mediated hepatocyte adhesion and proliferation in three dimensional tissue engineering scaffolds

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    Vasanthan, Kirthanashri S.; Sethuraman, Swaminathan; Parthasarathy, Meera, E-mail: meera_p@scbt.sastra.edu

    2015-08-26

    Asialoglycoprotein receptor (ASGPR) is one of the recognition motifs on the surface of hepatocytes, which promote their adhesion to extracellular matrix in liver tissue and appropriate artificial surfaces. ASGPR-mediated adhesion is expected to minimize trans-differentiation of hepatocytes in vitro that is generally observed in integrin-mediated adhesion. The aim of the present study is to verify the role of ASGPR in hepatocyte adhesion and proliferation in scaffolds for hepatic tissue engineering. Scanning Electrochemical Microscopy (SECM) is emerging as a suitable non-invasive analytical tool due to its high sensitivity and capability to correlate the morphology and activity of live cells. HepG2 cells and rat primary hepatocytes cultured in Polyvinyl alcohol (PVA)/Gelatin hydrogel scaffolds with and without galactose (a ligand for ASGPR) modification are studied using SECM. Systematic investigation of live cells cultured for different durations in scaffolds of different compositions (9:1 and 8:2 PVA:Gelatin with and without galactose) reveals significant improvement in cell–cell communication and proliferation on galactose incorporated scaffolds, thereby demonstrating the positive influence of ASGPR-mediated adhesion. In this work, we have also developed a methodology to quantify the respiratory activity and intracellular redox activity of live cells cultured in porous tissue engineering scaffolds. Using this methodology, SECM results are compared with routine cell culture assays viz., MTS ((1-Oxyl-2,2,5,5,-tetramethyl-Δ3-pyrroline-3-methyl) Methanethiosulfonate) and Albumin assays to demonstrate the better sensitivity of SECM. In addition, the present study demonstrates SECM as a reliable and sensitive tool to monitor the activity of live cells cultured in scaffolds for tissue engineering, which could be used on a routine basis. - Highlights: • A methodology for electrochemical imaging of polymer scaffolds is proposed. • The new methodology allows

  6. Human IgA as a heterovalent ligand: switching from the asialoglycoprotein receptor to secretory component during transport across the rat hepatocyte.

    Science.gov (United States)

    Schiff, J M; Fisher, M M; Jones, A L; Underdown, B J

    1986-03-01

    Asialoglycoproteins are taken up by the rat liver for degradation; rat polymeric IgA is taken up via a separate receptor, secretory component (SC), for quantitative delivery to bile. There is negligible uptake of these ligands by the converse receptor, and only a low level of missorting of ligands to opposite destinations. The two pathways are not cross-inhibitable and operate independently (Schiff, J.M., M. M. Fisher, and B. J. Underdown, 1984, J. Cell Biol., 98:79-89). We report here that when human IgA is presented as a ligand in the rat, it is processed using elements of both pathways. To study this in detail, different IgA fractions were prepared using two radiolabeling methods that provide separate probes for degradation or re-secretion. Behavior of intravenously injected human polymeric IgA in the rat depended on its binding properties. If deprived of SC binding activity by affinity adsorption or by reduction and alkylation, greater than 80% of human IgA was degraded in hepatic lysosomes; radioactive catabolites were released into bile by a leupeptin-inhibitable process. If prevented from binding to the asialoglycoprotein receptor by competition or by treatment with galactose oxidase, human IgA was cleared and transported to bile directly via SC, but its uptake was about fivefold slower than rat IgA. Untreated human IgA was taken up rapidly by the asialoglycoprotein receptor, but depended on SC binding to get to bile: the proportion secreted correlated 1:1 with SC binding activity determined in vitro, and the IgA was released into bile with SC still attached. These results demonstrate that human IgA is normally heterovalent: it is first captured from blood by the asialoglycoprotein receptor, but escapes the usual fate of asialoglycoproteins by switching to SC during transport. Since the biliary transit times of native human and rat IgA are the same, it is probable that the receptor switching event occurs en route. This implies that the two receptors briefly

  7. Asialoglycoprotein receptor facilitates infection of PLC/PRF/5 cells by HEV through interaction with ORF2.

    Science.gov (United States)

    Zhang, Li; Tian, Yabin; Wen, Zhiheng; Zhang, Feng; Qi, Ying; Huang, Weijin; Zhang, Heqiu; Wang, Youchun

    2016-12-01

    Although the biological and epidemiological features of hepatitis E virus (HEV) have been studied extensively in recent years, the mechanism by which HEV infects cells is still poorly understood. In this study, coimmunoprecipitation, pull-down, and ELISA were used to show that the HEV ORF2 protein interacts directly with the ectodomain of both ASGR1 and ASGR2. Susceptibility to HEV correlated positively with the expression level of surface asialoglycoprotein receptor (ASGPR) in cell lines. ASGPR-directed small interfering RNA (siRNA) in HEV-infected PLC/PRF/5 cells had no significant effect on HEV release, suggesting that ASGPR mainly regulates the viral binding and entry steps. Both the purified ASGPR ectodomain and anti-ASGPR antibodies disturbed the binding of HEV to PLC/PRF/5 cells. The classic ASGPR ligands asialofetuin, asialoganglioside, and fibronectin competitively inhibited the binding of HEV to hepatocytes in the presence of calcium. HeLa cell lines stably expressing ASGPR displayed increased HEV-binding capacity, whereas ASGPR-knockout PLC/PRF/5 cell lines had lower HEV-binding capacity. Thus, our study demonstrates that ASGPR is involved in and facilitates HEV infection by binding to ORF2. J. Med. Virol. 88:2186-2195, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Evaluation of asialoglycoprotein receptor imaging agent as a marker of hepatic ischemia-reperfusion injury and recovery

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    Toyama, Hiroshi; Suzuki, Kazuo; Naito, Aiko [Fujita Health Univ., Toyoake, Aichi (Japan)] [and others

    1999-06-01

    Protection of hepatocytes from ischemia-reperfusion injury is a clinically important issue. The purpose of this study was to evaluate changes in acute liver damage and recovery after ischemia-reperfusion in rats with asialoglycoprotein receptor (ASGP-R) ligand. Ischemia was induced by clamping the hepatoduodenal ligament for 90 min. At 1, 3, 24, 48 hr, 1 and 2 wk after reperfusion, I-125-GSA was injected. Five min after injection, blood samples were obtained and the liver was removed. Several regions from each lobe were dissected, weighed and counted. Mean uptakes (% dose/g) in the liver and blood samples were calculated. Histologic sections stained with hematoxylin-eosin (H-E) stain showed ischemic damage at 1 and 3 hr, and focal hepatocyte necrosis at 24 hr. Predominant massive necrosis was not seen. The mitotic index with H-E stain and proliferating cell nuclear antigen (PCNA) labeling index were highest at 1 wk, indicating liver regeneration. At 1 and 3 hr, liver uptake was significantly decreased, and blood uptake was significantly increased, indicating decreased tissue blood flow and ischemic damage. Liver uptake showed significant increases at 48 hr and 1 wk, and was the highest at 1 wk, indicating liver regeneration during the convalescence stage. ASGP-R binding may provide valuable information on ischemia-reperfusion injury and recovery. (author)

  9. Radiolabelled {sup 153}Sm-chelates of glycoconjugates: multivalence and topology effects on the targeting of the asialoglycoprotein receptor

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    Torres, S. [Centro de Quimica, Campus de Gualtar, Univ. do Minho, Braga (Portugal); Martins, J.A.; Andre, J.P.; Neves, M. [Inst. Tecnologico e Nuclear, Sacavem (Portugal); Santos, A.C.; Prata, M.I.M. [Servico de Biofisica, IBILI, Univ. de Coimbra (Portugal); Geraldes, C.F.G.C. [Dept. de Bioquimica, Centro de Espectroscopia RMN e Centro de Neurociencias e Biologia Celular, Univ. de Coimbra (Portugal)

    2007-07-01

    In this paper we report and discuss the biodistribution studies with Wistar rats of a series of {sup 153}Sm(III)-glycoconjugates, based on DO3A and DO2A(cis) scaffolds (DO3A = 1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane; DO2A(cis) = 1,4-bis(carboxymethyl)-1,4,7,10-tetraazacyclododecane). The effects of changing the sugar type (galactose, lactose and glucose), valency (mono and divalent) and topology on the targeting ability of the liver asialoglycoprotein receptor (ASGPR) are evaluated. Divalent glycoconjugates with different topologies were generated by a pendant glycodendrimeric (generation 1) architecture on a DO3A scaffold and by a linear DO2A(cis)-bis derivative. The results show that the galactose conjugates are more target efficient than the lactose analogues, while the glucose conjugates have no liver targeting ability. Divalent galactose conjugates are more efficiently targeted to the liver than the monovalent ones, while the dendrimeric topology of DO3A-Gal{sub 2} has higher targeting efficiency than that of the DO2A(cis)-Gal{sub 2}. (orig.)

  10. A new splice variant of the major subunit of human asialoglycoprotein receptor encodes a secreted form in hepatocytes.

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    Jia Liu

    Full Text Available BACKGROUND: The human asialoglycoprotein receptor (ASGPR is composed of two polypeptides, designated H1 and H2. While variants of H2 have been known for decades, the existence of H1 variants has never been reported. PRINCIPAL FINDINGS: We identified two splice variants of ASGPR H1 transcripts, designated H1a and H1b, in human liver tissues and hepatoma cells. Molecular cloning of ASGPR H1 variants revealed that they differ by a 117 nucleotide segment corresponding to exon 2 in the ASGPR genomic sequence. Thus, ASGPR variant H1b transcript encodes a protein lacking the transmembrane domain. Using an H1b-specific antibody, H1b protein and a functional soluble ASGPR (sASGPR composed of H1b and H2 in human sera and in hepatoma cell culture supernatant were identified. The expression of ASGPR H1a and H1b in Hela cells demonstrated the different cellular loctions of H1a and H1b proteins at cellular membranes and in intracellular compartments, respectively. In vitro binding assays using fluorescence-labeled sASGPR or the substract ASOR revealed that the presence of sASGPR reduced the binding of ASOR to cells. However, ASOR itself was able to enhance the binding of sASGPR to cells expressing membrane-bound ASGPR. Further, H1b expression is reduced in liver tissues from patients with viral hepatitis. CONCLUSIONS: We conclude that two naturally occurring ASGPR H1 splice variants are produced in human hepatocytes. A hetero-oligomeric complex sASGPR consists of the secreted form of H1 and H2 and may bind to free substrates in circulation and carry them to liver tissue for uptake by ASGPR-expressing hepatocytes.

  11. ASGR1 and ASGR2, the Genes that Encode the Asialoglycoprotein Receptor (Ashwell Receptor, Are Expressed in Peripheral Blood Monocytes and Show Interindividual Differences in Transcript Profile

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    Rebecca Louise Harris

    2012-01-01

    Full Text Available Background. The asialoglycoprotein receptor (ASGPR is a hepatic receptor that mediates removal of potentially hazardous glycoconjugates from blood in health and disease. The receptor comprises two proteins, asialoglycoprotein receptor 1 and 2 (ASGR1 and ASGR2, encoded by the genes ASGR1 and ASGR2. Design and Methods. Using reverse transcription amplification (RT-PCR, expression of ASGR1 and ASGR2 was investigated in human peripheral blood monocytes. Results. Monocytes were found to express ASGR1 and ASGR2 transcripts. Correctly spliced transcript variants encoding different isoforms of ASGR1 and ASGR2 were present in monocytes. The profile of transcript variants from both ASGR1 and ASGR2 differed among individuals. Transcript expression levels were compared with the hepatocyte cell line HepG2 which produces high levels of ASGPR. Monocyte transcripts were 4 to 6 orders of magnitude less than in HepG2 but nonetheless readily detectable using standard RT-PCR. The monocyte cell line THP1 gave similar results to monocytes harvested from peripheral blood, indicating it may provide a suitable model system for studying ASGPR function in this cell type. Conclusions. Monocytes transcribe and correctly process transcripts encoding the constituent proteins of the ASGPR. Monocytes may therefore represent a mobile pool of the receptor, capable of reaching sites remote from the liver.

  12. Epitope Structure of the Carbohydrate Recognition Domain of Asialoglycoprotein Receptor to a Monoclonal Antibody Revealed by High-Resolution Proteolytic Excision Mass Spectrometry

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    Stefanescu, Raluca; Born, Rita; Moise, Adrian; Ernst, Beat; Przybylski, Michael

    2011-01-01

    Recent studies suggest that the H1 subunit of the carbohydrate recognition domain (H1CRD) of the asialoglycoprotein receptor is used as an entry site into hepatocytes by hepatitis A and B viruses and Marburg virus. Thus, molecules binding specifically to the CRD might exert inhibition towards these diseases by blocking the virus entry site. We report here the identification of the epitope structure of H1CRD to a monoclonal antibody by proteolytic epitope excision of the immune complex and high-resolution MALDI-FTICR mass spectrometry. As a prerequisite of the epitope determination, the primary structure of the H1CRD antigen was characterised by ESI-FTICR-MS of the intact protein and by LC-MS/MS of tryptic digest mixtures. Molecular mass determination and proteolytic fragments provided the identification of two intramolecular disulfide bridges (seven Cys residues), and a Cys-mercaptoethanol adduct formed by treatment with β-mercaptoethanol during protein extraction. The H1CRD antigen binds to the monoclonal antibody in both native and Cys-alkylated form. For identification of the epitope, the antibody was immobilized on N-hydroxysuccinimide (NHS)-activated Sepharose. Epitope excision and epitope extraction with trypsin and FTICR-MS of affinity-bound peptides provided the identification of two specific epitope peptides (5-16) and (17-23) that showed high affinity to the antibody. Affinity studies of the synthetic epitope peptides revealed independent binding of each peptide to the antibody.

  13. Asialoglycoprotein-receptor-targeted hepatocyte imaging using {sup 99m}Tc galactosylated chitosan

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    Kim, Eun-Mi [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Jeong, Hwan-Jeong [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of)]. E-mail: jayjeong@chonbuk.ac.kr; Kim, Se-Lim [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Sohn, Myung-Hee [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Nah, Jae-Woon [Division of Applied Materials Engineering, Department of Polymer Science and Engineering, Sunchon National University, Sunchon, Jeonnam (Korea, Republic of); Bom, Hee-Seung [Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju (Korea, Republic of); Park, In-Kyu [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of); Cho, Chong-Su [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of)

    2006-05-15

    This study investigated the usefulness of {sup 99m}Tc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with {sup 99m}Tc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of {sup 99m}Tc HGC were studied in Balb/C mice. {sup 99m}Tc HGC and {sup 99m}Tc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a {gamma}-camera. After injection via the tail vein of the mice, {sup 99m}Tc HGC showed high selectivity for the liver, while {sup 99m}Tc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of {sup 99m}Tc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16{+-}2.72%, 16.11{+-}5.70% and 16.55{+-}2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. {sup 99m}Tc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function.

  14. Zonal differences in ethanol-induced impairments in receptor-mediated endocytosis of asialoglycoproteins in isolated rat hepatocytes

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    Casey, C.A.; Kragskow, S.L.; Sorrell, M.F.; Tuma, D.J. (Department of Veterans Affairs Medical Center, Omaha, NE (USA))

    1991-02-01

    We have shown previously that ethanol-induced defects in receptor-mediated endocytosis of asialoorosomucoid occurred as early as 1 wk after ethanol feeding. This study was undertaken as an initial attempt to establish a possible role of defective receptor-mediated endocytosis in liver injury by investigating whether differences exist in the effects of ethanol on receptor-mediated endocytosis in hepatocytes isolated from different regions of the liver. Perivenule cells, present in the distal half of the liver, are thought to be more susceptible to ethanol-induced liver injury than are the periportal cells located in the proximal half of the liver acini. For these studies, we fed male Sprague-Dawley rats for 7 days with liquid diets containing either ethanol (36% of calories) or isocaloric carbohydrate. Perivenule and periportal hepatocytes were then isolated using a digitonin-collagenase perfusion method. In control animals, cells isolated from the perivenule region bound significantly more ligand than did cells from the periportal region. Amounts of ligand internalized and degraded were also greater in perivenule than in periportal cells in these animals. After ethanol feeding, cells isolated from both the perivenule and periportal regions bound significantly less ligand than their respective controls. This impairment in surface and total binding was more pronounced in perivenule than in periportal cells. Internalization and degradation of the ligand were also more adversely affected in the centrilobular region as shown by decreases of greater than 60% in perivenule cells and by only 20% to 30% in periportal cells of ethanol-fed animals compared with controls.

  15. Design of cholesterol arabinogalactan anchored liposomes for asialoglycoprotein receptor mediated targeting to hepatocellular carcinoma: In silico modeling, in vitro and in vivo evaluation.

    Science.gov (United States)

    Pathak, Pankaj; Dhawan, Vivek; Magarkar, Aniket; Danne, Reinis; Govindarajan, Srinath; Ghosh, Sandipto; Steiniger, Frank; Chaudhari, Pradip; Gopal, Vijaya; Bunker, Alex; Róg, Tomasz; Fahr, Alfred; Nagarsenker, Mangal

    2016-07-25

    We have developed active targeting liposomes to deliver anticancer agents to ASGPR which will contribute to effective treatment of hepatocellular carcinoma. Active targeting is achieved through polymeric ligands on the liposome surface. The liposomes were prepared using reverse phase evaporation method and doxorubicin hydrocholoride, a model drug, was loaded using the ammonium sulphate gradient method. Liposomes loaded with DOX were found to have a particle size of 200nm with more than 90% entrapment efficiency. Systems were observed to release the drug in a sustained manner in acidic pH in vitro. Liposomes containing targeting ligands possessed greater and selective toxicity to ASGPR positive HepG2 cell lines due to specific ligand receptor interaction. Bio-distribution studies revealed that liposomes were concentrated in the liver even after 3h of administration, thus providing conclusive evidence of targeting potential for formulated nanosystems. Tumor regression studies indicated greater tumor suppression with targeted liposomes thereby establishing superiority of the liposomal system. In this work, we used a novel methodology to guide the determination of the optimal composition of the targeting liposomes: molecular dynamics (MD) simulation that aided our understanding of the behaviour of the ligand within the bilayer. This can be seen as a demonstration of the utility of this methodology as a rational design tool for active targeting liposome formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Role of sialic acid for platelet life span: exposure of beta-galactose results in the rapid clearance of platelets from the circulation by asialoglycoprotein receptor-expressing liver macrophages and hepatocytes

    DEFF Research Database (Denmark)

    Sørensen, Anne Louise; Rumjantseva, Viktoria; Nayeb-Hashemi, Sara

    2009-01-01

    Although surface sialic acid is considered a key determinant for the survival of circulating blood cells and glycoproteins, its role in platelet circulation lifetime is not fully clarified. We show that thrombocytopenia in mice deficient in the St3gal4 sialyltransferase gene (St3Gal-IV(-/-) mice)...

  17. Generation of an ASGR1 homozygous mutant human embryonic stem cell line WAe001-A-6 using CRISPR/Cas9

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    Yingying Xu

    2017-07-01

    Full Text Available The gene asialoglycoprotein receptor 1 (ASGR1 encodes a subunit of the asialoglycoprotein receptor. Here we report the generation of a human embryonic stem cell line WAe001-A-6 harbouring homozygous ASGR1 mutations using CRISPR/Cas9. The mutation involves a 37 bp deletion, resulting in a frame shift. The homozygous knockout WA01 cell line maintains a normal karyotype, typical stem cell morphology, pluripotency and differentiation potential in vitro.

  18. Clinical application of TcGSA

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    Kokudo, Norihiro E-mail: KOKUDO-2SU@h.u-tokyo.ac.jp; Vera, David R.; Makuuchi, Masatoshi

    2003-11-01

    Asialoglycoprotein receptor (ASGP-R) is a hepatic cell surface receptor specific for galactose-terminated glycoprotein. The {sup 99m}Tc-labeled asialoglycoprotein analog, TcGSA (galactosyl-human serum albumin-diethylenetriamine-pentaacetic acid) has been applied to human hepatic receptor imaging. This method is unique and provides information that is totally independent of the ICG test or Child-Turcotte Score. However, simple parameters, HH15 or LHL15 are no better than conventional Child-Turcotte Score. Parameters obtained from kinetic modeling were useful in detecting liver cirrhosis or postoperative liver failure. They provide quantitative data on functioning liver mass. Considering the moderate cost and widespread availability of gamma cameras, a TcGSA test should be performed on patients whose liver function are not adequately estimated by an ICG test or a Child-Turcotte score.

  19. Galactose-specific recognition system of mammalian liver: receptor distribution on the hepatocyte cell surface

    OpenAIRE

    1981-01-01

    An isolated perfused liver system was used to study the distribution of asialoglycoprotein (ASGP) binding sites on rat hepatocyte cell surfaces. The number of surface receptors was quantitated by monitoring clearance of 125I-labeled ligands from the perfusate medium under two conditions that blocked their internalization: low temperature (less than 5 degrees C) or brief formaldehyde fixation. The cell surface distribution of binding sites was visualized in the electron microscope with either ...

  20. Receptor-mediated transport of oligodeoxynucleotides into hepatic cells.

    Science.gov (United States)

    Reinis, M; Damková, M; Korec, E

    1993-04-01

    Receptor-mediated endocytosis was employed for a highly efficient transport of oligodeoxynucleotides into hepatoma cell line PLC/PRF/5. The oligodeoxynucleotides were bound to the asialofetuin-poly-L-lysine conjugate and this complex was internalized by the cells via asialoglycoprotein receptor, an endocytic receptor unique for hepatocytes. Binding of the oligodeoxynucleotides to the complex dramatically increased their cellular uptake more than 20-fold. Chloroquine, a lysosomatropic agent, further increased the transport of the complex but not of the free oligodeoxynucleotides.

  1. Variation of fibrinogen oligosaccharide structure in the acute phase response: Possible haemorrhagic implications

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    Stephen O. Brennan

    2015-06-01

    Conclusions and implications: The failure of incorporation Gal excludes the possibility of the hepatic NAcNeu Gal transferase capping the oligosaccharides with sialic acid. This has two desirable haemostatic outcomes: fibrin monomers will polymerise and form clots more rapidly, and two galactose residues can never be exposed diminishing uptake of the protein by the asialoglycoprotein receptor and ramping up concentration at a time of challenge.

  2. CLINICAL DIAGNOSTIC VALUE OF AUTOANTIBODIES IN THE DIAGNOSIS OF AUTOIMMUNE LIVER DISEASES

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    V. V. Bazarnyi

    2015-01-01

    Full Text Available We are studied the 15 patients with autoimmune liver diseases and 36 patients without autoimmune pathology found the diagnostic value of antinuclear and antimitochondrial autoantibodies (AMA-M2 tests, and antibodies to asialoglycoprotein receptor (anti-ASGPR. Based on the ROC analysis showed that the diagnostic sensitivity and diagnostic specificity of AMA-M2 was 73% and 100% and for anti-ASGPR – 60% and 77%, respectively. Therefore, the test for anti-ASGPR in autoimmune diseases of the liver showed no advantages over standart tests, and its using in clinical practice requires clarification. 

  3. PAMAM-pullulan conjugates as targeted gene carriers for liver cell.

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    Askarian, Saeedeh; Abnous, Khalil; Ayatollahi, Sara; Farzad, Sara Amel; Oskuee, Reza Kazemi; Ramezani, Mohammad

    2017-02-10

    Targeted nano-carriers are highly needed to promote nucleic acid delivery into the specific cell for therapeutic approaches. Pullulan as a linear carbohydrate has an intrinsic liver targeting property interacting with asialoglycoprotein receptor (ASGPR) found on liver cells. In the present study, we developed polyamidoamine (PAMAM)-pullulan conjugates and investigated their targeting activity in delivering gene into liver cells. The particle size, zeta potential, buffering capacity and ethidium bromide exclusion assays of the conjugates were evaluated. The cytotoxicity and transfection efficiency of new derivatives were assessed following in vitro transfection of HepG2 (receptor positive) and N2A (receptor negative) cell lines. Size of conjugated polymers ranged between 118 and 184 nanometers and their cytotoxicity were similar to PAMAM. Among six produced nanocarriers, G4PU4 and G5PU4 enhanced transfection efficiency in HepG2 cells compared to unmodified PAMAM. Therefore, the PAMAM-pullulan derivatives seem to improve delivery of nucleic acids into the liver cells expressing asialoglycoprotein receptor with minimal transfection in non-targeted cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Role of sialylation in determining the pharmacokinetics of neutrophil inhibitory factor (NIF) in the Fischer 344 rat.

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    Webster, R; Taberner, J; Edgington, A; Guhan, S; Varghese, J; Feeney, H; Blocker, L; Jezequel, S G

    1999-11-01

    1. Recombinant neutrophil inhibitory factor (NIF) is a glycoprotein. Its amino acid sequence remains constant and has a molecular weight of 28.9 kD. However, approximately 40% of the total molecular weight consists of glycans with variable structure. 2. The pharmacokinetics of 11 different NIF batches with varying extents and patterns of sialylation have been investigated in the Fischer 344 rat following intravenous administration. These data indicate that reducing the extent of NIF sialylation reduces the half-life of the molecule due to an increase in the systemic clearance. Also, an increase in the number of unsialylated or neutral glycans may increase the volume of distribution of NIF, although this effect is marginal. 3. Isolated perfused rat liver (IPRL) investigations have shown that sialylated NIF has a low hepatic extraction (NIF has an extraction that is > 20-fold higher. Co-administration of asialo NIF with asialo fetuin (a protein cleared by hepatic asialoglycoprotein receptor (possibly galactose)-mediated uptake reduced the hepatic extraction of asialo NIF. 4. These data suggest that NIF molecules that have free sugar moieties (possibly galactose) interact with an asialoglycoprotein receptor (possibly galactose-mediated) in the liver (parenchymal cells/hepatocytes). Interaction with this receptor leads to cellular internalization and degradation.

  5. Alginate-based microcapsules with galactosylated chitosan internal for primary hepatocyte applications.

    Science.gov (United States)

    Lou, Ruyun; Xie, Hongguo; Zheng, Huizhen; Ren, Ying; Gao, Meng; Guo, Xin; Song, Yizhe; Yu, Weiting; Liu, Xiudong; Ma, Xiaojun

    2016-12-01

    Alginate-galactosylated chitosan/polylysine (AGCP) microcapsules with excellent stability and high permeability were developed and employed in primary hepatocyte applications. The galactosylated chitosan (GC), synthesized via the covalent coupling of lactobionic acid (LA) with low molecular weight and water-soluble chitosan (CS), was ingeniously introduced into the core of alginate microcapsules by regulating the pH of gelling bath. The internal GC of the microcapsules simultaneously provided a large number of binding sites for the hepatocytes and further promoted the hepatocyte-matrix interactions via the recognition of asialoglycoprotein receptors (ASGPRs) on the hepatocyte surface, and afforded the AGCP microcapsules an excellent stability via the electrostatic interactions with alginate. As a consequence, primary hepatocytes in AGCP microcapsules demonstrated enhanced viability, urea synthesis, albumin secretion, and P-450 enzyme activity, showing great prospects for hepatocyte applications in microcapsule system. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Design of intrahepatocyte copper(I) chelators as drug candidates for Wilson's disease.

    Science.gov (United States)

    Gateau, Christelle; Delangle, Pascale

    2014-05-01

    Wilson's disease is an autosomal recessive disease caused by mutations on the ATP7B gene found on chromosome 13. Since the corresponding ATPase is in charge of copper (Cu) distribution and excretion in the liver, its malfunctioning leads to Cu overload. This short review deals with treatments of this rare disease, which aim at decreasing Cu toxicity and are, therefore, based on chelation therapy. The drugs used since the 1950s are described first, then a novel approach developed in our laboratory is presented. Since the liver is the main organ of Cu distribution in the body, we targeted the pool of intracellular Cu in hepatocytes. This Cu pool is in the +1 oxidation state, and therefore soft sulfur ligands inspired from binding sites found in metallothioneins were developed. Their targeting to the hepatocytes by functionalization with ligands of the asialoglycoprotein receptor led to their cellular incorporation and intracellular Cu chelation. © 2014 New York Academy of Sciences.

  7. Synthesis of novel galactose functionalized gold nanoparticles and its radiosensitizing mechanism.

    Science.gov (United States)

    Zhu, Chuan-Dong; Zheng, Qin; Wang, Li-Xue; Xu, Han-Feng; Tong, Jin-Long; Zhang, Quan-An; Wan, Yuan; Wu, Jian-Qing

    2015-10-09

    Biocompatible gold nanoparticles (GNPs) are potentially practical and efficient agents in cancer radiotherapy applications. In this study, we demonstrated that GNPs can significantly modulate irradiation response of hepatocellular carcinoma cells in vitro and investigated the underlying mechanisms. We co-grafted galactose (GAL) targeting hepatocyte specific asialoglycoprotein receptor and Polyethylene Glycol (PEG) onto GNPs surfaces to increase GNPs targeting specificity and stability. This novel GAL-PEG-GNPs and bare GNPs show similar appearance and cytotoxicity profiles, while more GAL-PEG-GNPs can be effectively uptaken and could enhance cancer cell killing. GAL-PEG-GNPs have better radiosensitization to HepG2. The sensitization mechanism of GAL-PEG-GNPs is related to the apoptotic gene process activated by generation of a large amount of free radicals induced by GNPs.

  8. Targeting and molecular imaging of HepG2 cells using surface-functionalized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Rathinaraj, Pierson [Auckland University of Technology, Institute of Biomedical Technologies (New Zealand); Lee, Kyubae; Choi, Yuri; Park, Soo-Young [Kyungpook National University, School of Applied Chemical Engineering, Graduate School (Korea, Republic of); Kwon, Oh Hyeong [Kumoh National Institute of Technology, Department of Polymer Science and Engineering (Korea, Republic of); Kang, Inn-Kyu, E-mail: ikkang@knu.ac.kr [Kyungpook National University, School of Applied Chemical Engineering, Graduate School (Korea, Republic of)

    2015-07-15

    Mercaptosuccinic acid (M)-conjugated gold nanoparticles (GM) were prepared and characterized by transmission electron microscope and dynamic light scattering. M was used to improve the monodispersity and non-specific intracellular uptake of nanoparticles. Lactobionic acid (L) was subsequently conjugated to the GM to target preferentially HepG2 cells (liver cancer cells) that express asialoglycoprotein receptors (ASGPR) on their membrane surfaces and facilitate the transit of nanoparticles across the cell membrane. The mean size of lactobionic acid-conjugated gold nanoparticle (GL) was approximately 10 ± 0.2 nm. Finally, the Atto 680 dye (A6) was coupled to the nanoparticles to visualize their internalization into HepG2 cells. The interaction of surface-modified gold nanoparticles with HepG2 cells was studied after culturing cells in media containing the GM or L-conjugated GM (GL)

  9. Cellular uptake of fluorophore-labeled glyco-DNA-gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Witten, Katrin G.; Ruff, Julie [RWTH Aachen University, Institute of Inorganic Chemistry and JARA - Fundamentals of Future Information Technology (Germany); Mohr, Anne; Goertz, Dieter; Recker, Tobias; Rinis, Natalie [RWTH Aachen University, Institute of Biochemistry and Molecular Biology, University Hospital Aachen (Germany); Rech, Claudia; Elling, Lothar [RWTH Aachen University, Laboratory for Biomaterials, Institute of Biotechnology and Helmholtz-Institute for Biomedical Engineering (Germany); Mueller-Newen, Gerhard [RWTH Aachen University, Institute of Biochemistry and Molecular Biology, University Hospital Aachen (Germany); Simon, Ulrich, E-mail: ulrich.simon@ac.rwth-aachen.de [RWTH Aachen University, Institute of Inorganic Chemistry and JARA - Fundamentals of Future Information Technology (Germany)

    2013-10-15

    DNA-functionalized gold nanoparticles (AuNP-DNA) were hybridized with complementary di-N-acetyllactosamine-(di-LacNAc, [3Gal({beta}1-4)GlcNAc({beta}1-]2)-modified oligonucleotides to form glycol-functionalized particles, AuNP-DNA-di-LacNAc. While AuNP-DNA are known to be taken up by cells via scavenger receptors, glycol-functionalized particles have shown to be taken up via asialoglycoprotein receptors (ASGP-R). In this work, the interaction of these new particles with HepG2 cells was analyzed, which express scavenger receptors class B type I (SR-BI) and ASGP-R. To study the contribution of these receptors as potential mediators for cellular uptake, receptor-blocking experiments were performed with d-lactose, a ligand for ASGP-R, Fucoidan, a putative ligand for SR-BI, and a SR-BI blocking antibody. Labeling with Cy5-modified DNA ligands enabled us to monitor the particle uptake by confocal fluorescence microscopy and flow cytometry, in order to discriminate the two putative pathways by competitive binding studies. While SR-BI-antibody and d-lactose had no inhibiting effects on particle uptake Fucoidan led to a complete inhibition. Thus, a receptor-mediated uptake by the two receptors studied could not be proven and therefore other uptake mechanisms have to be considered.

  10. Scavenger Receptor C-Type Lectin Binds to the Leukocyte Cell Surface Glycan Lewis By a Novel Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, H.; Taylor, M.E.; Weis, W.I.; /Stanford U., Med. School /Imperial Coll., London

    2007-07-10

    The scavenger receptor C-type lectin (SRCL) is unique in the family of class A scavenger receptors, because in addition to binding sites for oxidized lipoproteins it also contains a C-type carbohydrate-recognition domain (CRD) that interacts with specific glycans. Both human and mouse SRCL are highly specific for the Lewis(x) trisaccharide, which is commonly found on the surfaces of leukocytes and some tumor cells. Structural analysis of the CRD of mouse SRCL in complex with Lewis(x) and mutagenesis show the basis for this specificity. The interaction between mouse SRCL and Lewis(x) is analogous to the way that selectins and DC-SIGN bind to related fucosylated glycans, but the mechanism of the interaction is novel, because it is based on a primary galactose-binding site similar to the binding site in the asialoglycoprotein receptor. Crystals of the human receptor lacking bound calcium ions reveal an alternative conformation in which a glycan ligand would be released during receptor-mediated endocytosis.

  11. Degradation of asialoprothrombin and its relevance to prothrombin turnover

    Energy Technology Data Exchange (ETDEWEB)

    Vostal, J.G.

    1986-01-01

    As a part of their turnover, serum glycoproteins have been thought to be cleared from plasma and degraded after an initial conversion to an asialogylcoprotein intermediate. The authors have examined this possibility with the plasma protein prothrombin. Bovine prothrombin and its asialo derivative were prepared and radioiodinated by conventional methods. In vivo plasma half lives of trichloroacetic acid (TCA) precipitable radioactivity were estimated in heparinized and anesthetized rats following and injection of the individual proteins into the femoral vein. For prothrombin, the half life was 3.2 hours with very little plasma TCA soluble radioactive products formed over 3 hours. Asialo-prothrombin's half life was only 1.1 minutes with soluble radioactive material increasing greatly during the initial 30 minutes. Simultaneous administration of competing doses of asialofetuin greatly increased the apparent half life of asialoprothrombin. The uptake and the release of TCA soluble radioactivity from liver was also delayed. Studies with isolated hepatocytes further demonstrated that asialoprothrombin was taken up by the cells and eventually degraded in the lysosomes. However, single or multiple injections of the highest dose of asialofetuin had no effect on /sup 125/I-prothrombin half life plasma soluble radioactivity or accumulation in the liver. The data indicate that while exogenously administered asialoprothrombin is apparently cleared from circulation by a hepatic asialoglycoprotein receptor, prothrombin, even though accumulated by the liver, is not.

  12. Identification of GalNAc-Conjugated Antisense Oligonucleotide Metabolites Using an Untargeted and Generic Approach Based on High Resolution Mass Spectrometry.

    Science.gov (United States)

    Husser, Christophe; Brink, Andreas; Zell, Manfred; Müller, Martina B; Koller, Erich; Schadt, Simone

    2017-06-20

    Antisense oligonucleotides linked by phosphorothioates are an important class of therapeutics under investigation in various pharmaceutical companies. Antisense oligonucleotides may be coupled to high-affinity ligands (triantennary N-acetyl galactosamine = GalNAc) for hepatocyte-specific asialoglycoprotein receptors (ASGPR) to enhance uptake to hepatocytes and to increase potency. Since disposition and biotransformation of GalNAc-conjugated oligonucleotides is different from unconjugated oligonucleotides, appropriate analytical methods are required to identify main cleavage sites and degradation products of GalNAc conjugated and unconjugated oligonucleotides in target cells. A highly sensitive method was developed to identify metabolites of oligonucleotides using capillary flow liquid chromatography with column switching coupled to a high resolution Orbitrap Fusion mass spectrometer. Detection of GalNAc-conjugated oligonucleotides and their metabolites was achieved by combining full scan MS with two parallel MS2 experiments, one data-dependent scan and an untargeted MS2 experiment (all ion fragmentation) applying high collision energy. In the all ion fragmentation scan, a diagnostic fragment originating from the phosphorothioate backbone (O2PS-: m/z 94.936) was formed efficiently upon collisional activation. Based on this fragment an accurate determination of metabolites of oligonucleotides was achieved, independent of their sequence or conjugation in an untargeted but highly selective manner. The method was effectively applied to investigate uptake and metabolism of GalNAc-conjugated oligonucleotides in incubations of primary rat hepatocytes; the elucidation of expected and unexpected degradation products was achieved in subnanomolar range.

  13. Galactosylated iodine-based small molecule I.V. CT contrast agent for bile duct imaging.

    Science.gov (United States)

    Jung, Yeonjin; Hwang, Hee Sook; Na, Kun

    2018-04-01

    Computed tomography (CT) with contrast plays an important role as a clinical diagnostic tool but still has a limited diagnostic range. In this work, we developed a novel injectable iodine-based small molecule CT contrast agent, even can be used for bile duct diagnostics. The bile duct diagnosable CT contrast agent (BDICA) is synthesized with 5-amino-2,4,6-triiodoisophthaloyl dichloride (ATIPC), tromethamine and lactobionic acid (LBA) for asialoglycoprotein receptor (ASGPR) targeted delivery via receptor-mediated endocytosis and transport to the bile canaliculi. Specific binding to the ASGPRs was confirmed by in vitro cellular uptake in HepG2 cells (ASGPR positive) and HCT 116 cells (ASGPR negative). Compared to iohexol, BDICA has equal in vivo distribution and a 13-fold iodine increase in content was observed in bile juice after BDICA injection. The radiopaque contrast effect in the bile duct has been clearly shown in in vivo CT scans. Furthermore, within 36 h, 91.3% of the BDICA was eliminated without organ damage, which verified the overall safety of the contrast agent. BDICA not only provides sufficient contrast images similar to iohexol, but also provides superior images of the bile duct. Based on recent studies, it has been shown that BDICA is a promising, safe and effective contrast agent for CT imaging of the organs and soft tissues, including the bile duct. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Fabrication of 3D-culture platform with sandwich architecture for preserving liver-specific functions of hepatocytes using 3D bioprinter.

    Science.gov (United States)

    Arai, Kenichi; Yoshida, Toshiko; Okabe, Motonori; Goto, Mitsuaki; Mir, Tanveer Ahmad; Soko, Chika; Tsukamoto, Yoshinari; Akaike, Toshihiro; Nikaido, Toshio; Zhou, Kaixuan; Nakamura, Makoto

    2017-06-01

    The development of new three-dimensional (3D) cell culture system that maintains the physiologically relevant signals of hepatocytes is essential in drug discovery and tissue engineering research. Conventional two-dimensional (2D) culture yields cell growth, proliferation, and differentiation. However, gene expression and signaling profiles can be different from in vivo environment. Here, we report the fabrication of a 3D culture system using an artificial scaffold and our custom-made inkjet 3D bioprinter as a new strategy for studying liver-specific functions of hepatocytes. We built a 3D culture platform for hepatocytes-attachment and formation of cell monolayer by interacting the galactose chain of galactosylated alginate gel (GA-gel) with asialoglycoprotein receptor (ASGPR) of hepatocytes. The 3D geometrical arrangement of cells was controlled by using 3D bioprinter, and cell polarity was controlled with the galactosylated hydrogels. The fabricated GA-gel was able to successfully promote adhesion of hepatocytes. To observe liver-specific functions and to mimic hepatic cord, an additional parallel layer of hepatocytes was generated using two gel sheets. These results indicated that GA-gel biomimetic matrices can be used as a 3D culture system that could be effective for the engineering of liver tissues. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1583-1592, 2017. © 2017 Wiley Periodicals, Inc.

  15. A carbohydrate-antioxidant hybrid polymer reduces oxidative damage in spermatozoa and enhances fertility.

    Science.gov (United States)

    Fleming, Craig; Maldjian, André; Da Costa, Daniel; Rullay, Attvinder K; Haddleton, David M; St John, Justin; Penny, Paul; Noble, Raymond C; Cameron, Neil R; Davis, Benjamin G

    2005-10-01

    Gamete-gamete interactions are critically modulated by carbohydrate-protein interactions that rely on the carbohydrate-selective recognition of polyvalent carbohydrate structures. A galactose-binding protein has been identified in mammalian spermatozoa that has similarity to the well-characterized hepatic asialoglycoprotein receptor. With the aim of exploiting the ability of this class of proteins to bind and internalize macromolecules displaying galactose, we designed hybrid carbohydrate-antioxidant polymers to deliver antioxidant vitamin E (alpha-tocopherol) to porcine spermatozoa. Treatment of sperm cells with one hybrid polymer in particular produced large increases in intracellular sperm levels of alpha-tocopherol and greatly reduced endogenous fatty acid degradation under oxidative stress. The polymer-treated spermatozoa had enhanced physiological properties and longer half-lives, which resulted in enhanced fertilization rates. Our results indicate that hybrid polymer delivery systems can prolong the functional viability of mammalian spermatozoa and improve fertility rates, and that our functionally guided optimization strategy can be applied to the discovery of active glycoconjugate ligands.

  16. Cloning expeditions: risky but rewarding.

    Science.gov (United States)

    Lodish, Harvey

    2013-12-01

    In the 1980s, a good part of my laboratory was using the then-new recombinant DNA techniques to clone and characterize many important cell surface membrane proteins: GLUT1 (the red cell glucose transporter) and then GLUT2 and GLUT4, the red cell anion exchange protein (Band 3), asialoglycoprotein receptor subunits, sucrase-isomaltase, the erythropoietin receptor, and two of the subunits of the transforming growth factor β (TGF-β) receptor. These cloned genes opened many new fields of basic research, including membrane insertion and trafficking of transmembrane proteins, signal transduction by many members of the cytokine and TGF-β families of receptors, and the cellular physiology of glucose and anion transport. They also led to many insights into the molecular biology of several cancers, hematopoietic disorders, and diabetes. This work was done by an exceptional group of postdocs and students who took exceptionally large risks in developing and using novel cloning technologies. Unsurprisingly, all have gone on to become leaders in the fields of molecular cell biology and molecular medicine.

  17. [Preparation of hepatic targeting antivirus agent NGA-ACV and its targeting property].

    Science.gov (United States)

    Fan, J Z; Li, T L; Pang, Q J; Guan, C T; He, Y; Su, K Y

    1996-01-01

    Neoglycoalbumin (NGA), a special ligend of asialoglycoprotein receptor on the hepatocyte, was linked via a butanediacyl bridge to acyclovir to form a conjugate NGA-ACV. By using DTA (Differential thermoanalysis) and HPLC analysis, ACV was shown to be connected with NGA by covalent bonds and stable in blood. The radio-biodistribution of 131I-NGA-ACV with high drug density in vivo was carried out in mice. The maximum absorption of 131I-NGA-ACV in liver was 81.7 +/- 10.4% at 5 min. The radioimage of 131I-NGA-ACV with high or low drug density in rabbit showed no significant difference in liver targeting property. The competitive connection tests indicated that 131I-NGA-ACV was concentrated in liver through receptor mediated mechanism. A tentative test of antihepatitis B of NGA-ACV and ACV in vitro showed that the effective dose of the former was significantly lower than that of the latter.

  18. A novel hypothesis for an alkaline phosphatase 'rescue' mechanism in the hepatic acute phase immune response.

    Science.gov (United States)

    Pike, Adrianne F; Kramer, Nynke I; Blaauboer, Bas J; Seinen, Willem; Brands, Ruud

    2013-12-01

    The liver isoform of the enzyme alkaline phosphatase (AP) has been used classically as a serum biomarker for hepatic disease states such as hepatitis, steatosis, cirrhosis, drug-induced liver injury, and hepatocellular carcinoma. Recent studies have demonstrated a more general anti-inflammatory role for AP, as it is capable of dephosphorylating potentially deleterious molecules such as nucleotide phosphates, the pathogenic endotoxin lipopolysaccharide (LPS), and the contact clotting pathway activator polyphosphate (polyP), thereby reducing inflammation and coagulopathy systemically. Yet the mechanism underlying the observed increase in liver AP levels in circulation during inflammatory insults is largely unknown. This paper hypothesizes an immunological role for AP in the liver and the potential of this system for damping generalized inflammation along with a wide range of ancillary pathologies. Based on the provided framework, a mechanism is proposed in which AP undergoes transcytosis in hepatocytes from the canalicular membrane to the sinusoidal membrane during inflammation and the enzyme's expression is upregulated as a result. Through a tightly controlled, nucleotide-stimulated negative feedback process, AP is transported in this model as an immune complex with immunoglobulin G by the asialoglycoprotein receptor through the cell and secreted into the serum, likely using the receptor's State 1 pathway. The subsequent dephosphorylation of inflammatory stimuli by AP and uptake of the circulating immune complex by endothelial cells and macrophages may lead to decreased inflammation and coagulopathy while providing an early upstream signal for the induction of a number of anti-inflammatory gene products, including AP itself. © 2013.

  19. Accurate Estimation of Functional Liver Volume Using Gd-EOB-DTPA MRI Compared to MDCT/99mTc-SPECT Fusion Imaging.

    Science.gov (United States)

    Morine, Yuji; Enkhbold, Chinbold; Imura, Satoru; Ikemoto, Tetsuya; Iwahashi, Syuichi; Saito, Y U; Yamada, Shinichiro; Utsunomiya, Tohru; Shimada, Mitsuo

    2017-10-01

    We assessed the utility of dynamic magnetic resonance imaging (MRI) with gadoxetate-ethoxybenzyl-diethylenetriamine penta-aceticpenta-acetic acid (Gd-EOB-DTPA) (EOB-MRI) for estimating functional liver volume compared to 99m Tc-galactosyl albumin single-photon-emission computed tomography ( 99m Tc-GSA SPECT). Regional functional liver volume (left lateral, medial, right anterior, right posterior) of 58 hepatectomized patients was assessed using EOB-MRI and 99m Tc-GSA SPECT, and compared to the actual liver volume with MDCT-3D volumetry. 99m Tc-GSA SPECT found a significantly lower functional volume of the left lateral section than the actual volume found by MDCT-3D volumetry (p=0.003) and EOB-MRI (pliver volume of right anterior section found with 99m Tc-GSA SPECT was significantly higher than that found by MDCT-3D volumetry (p=0.04), despite no differences in asialoglycoprotein receptor 1 (ASGR1) or ATP-dependent organic anion transporting polypeptide 1 (OATP) expression between the left lateral and right anterior sections. 99m Tc-GSA SPECT might underestimate the function of the left lobe and overestimate that of the right lobe. Therefore, EOB-MRI could be better for estimating the true regional functional liver reserve. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  20. Cloning Expeditions: Risky but Rewarding

    Science.gov (United States)

    2013-01-01

    In the 1980s, a good part of my laboratory was using the then-new recombinant DNA techniques to clone and characterize many important cell surface membrane proteins: GLUT1 (the red cell glucose transporter) and then GLUT2 and GLUT4, the red cell anion exchange protein (Band 3), asialoglycoprotein receptor subunits, sucrase-isomaltase, the erythropoietin receptor, and two of the subunits of the transforming growth factor β (TGF-β) receptor. These cloned genes opened many new fields of basic research, including membrane insertion and trafficking of transmembrane proteins, signal transduction by many members of the cytokine and TGF-β families of receptors, and the cellular physiology of glucose and anion transport. They also led to many insights into the molecular biology of several cancers, hematopoietic disorders, and diabetes. This work was done by an exceptional group of postdocs and students who took exceptionally large risks in developing and using novel cloning technologies. Unsurprisingly, all have gone on to become leaders in the fields of molecular cell biology and molecular medicine. PMID:24061478

  1. Enhanced uptake of lactosaminated human albumin by rat hepatocarcinomas: implications for an improved chemotherapy of primary liver tumors.

    Science.gov (United States)

    Di Stefano, Giuseppina; Fiume, Luigi; Bolondi, Luigi; Lanza, Marcella; Pariali, Milena; Chieco, Pasquale

    2005-08-01

    The hepatocyte receptor for asialoglycoproteins (ASGP-R) internalizes macromolecules exposing galactosyl residues (MEGRs) which can be used as liver-addressed drug carriers. This receptor was also found on the cells of the large majority of well differentiated hepatocarcinomas (HCCs). The aim of the present experiments was to ascertain whether ASGP-R of HCCs is functionally active and these tumors can internalize higher quantities of MEGRs than extra-hepatic tissues. We injected radioactive lactosaminated human albumin (L-HSA) in rats with HCCs produced by nitroso-diethylamine and measured the radioactivity of tumors, surrounding liver, heart, intestine and kidney. L-HSA is a MEGR successfully used in humans as a hepatotropic drug carrier. The levels of radioactivity of HCCs were two to three times lower than those of surrounding liver, but several times higher than those of extra-hepatic tissues. L-HSA accumulation in the tumors mainly occurred via the ASGP-R, as indicated by the 20 times lower penetration of non-lactosaminated HSA. L-HSA uptake by the well-differentiated tumors were four times higher compared with that by the poorly differentiated forms. The present results suggest that in the chemotherapy of HCCs expressing the ASGP-R the extra-hepatic toxicity of anticancer agents can be reduced by conjugation to L-HSA.

  2. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    Energy Technology Data Exchange (ETDEWEB)

    Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

    2014-02-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

  3. DNA Nanocarriers for Systemic Administration: Characterization and In Vivo Bioimaging in Healthy Mice

    Directory of Open Access Journals (Sweden)

    Stephanie David

    2013-01-01

    Full Text Available We hereby present different DNA nanocarriers consisting of new multimodular systems (MMS, containing the cationic lipid dioleylaminesuccinylparomomycin (DNA MMS DOSP, or bis (guanidinium-tren-cholesterol (DNA MMS BGTC, and DNA lipid nanocapsules (DNA LNCs. Active targeting of the asialoglycoprotein receptor (ASGP-R using galactose as a ligand for DNA MMS (GAL DNA MMS and passive targeting using a polyethylene glycol coating for DNA LNCs (PEG DNA LNCs should improve the properties of these DNA nanocarriers. All systems were characterized via physicochemical methods and the DNA payload of DNA LNCs was quantified for the first time. Afterwards, their biodistribution in healthy mice was analyzed after encapsulation of a fluorescent dye via in vivo biofluorescence imaging (BFI, revealing various distribution profiles depending on the cationic lipid used and their surface characteristics. Furthermore, the two vectors with the best prolonged circulation profile were administered twice in healthy mice revealing that the new DNA MMS DOSP vectors showed no toxicity and the same distribution profile for both injections, contrary to PEG DNA LNCs which showed a rapid clearance after the second injection, certainly due to the accelerated blood clearance phenomenon.

  4. Establishment of a fluorescence-based method to evaluate endocytosis of desialylated glycoproteins in vitro.

    Science.gov (United States)

    Luo, Cheng; Chen, Song; Xu, Na; Sai, Wen Bo; Zhao, Wei; Li, Ying Chun; Hu, Xiao Jing; Tian, Hong; Gao, Xiang Dong; Yao, Wen Bing

    2017-04-01

    Insufficient sialylation can result in rapid clearance of therapeutic glycoproteins by intracellular degradation, which is mainly mediated by asialoglycoprotein receptors (ASGPRs) on hepatic cells. In contrast, for glycoproteins, a long half-life is often related to high level of terminal sialic acid. These could be extremely important for insufficient sialylated biomedicines in clinic, and development of therapeutic glycoproteins in laboratory. However, how the desialylated glycoproteins are removed and how to evaluate the ASGPRs mediated endocytosis in vitro needs further investigate. Herein we described an integrative characterization of ASGPRs in vitro to elucidate its endocytosis properties. The endocytosis was determined by a fluorescence-based quantization method. The results showed that the ASGPRs could bind to poorly sialylated glycoproteins including asialofetuin and low sialylated recombinant Factor VIIa with a relatively higher ASGPRs binding affinity, and induce a more rapid endocytosis in vitro. Moreover, the mechanism under the internalization of ASGPRs was also investigated, which was found to depend on clathrin and caveolin. Utilizing the relative fluorescence quantification can be suitable for measurement of insufficient sialylated glycoprotein endocytosis and quality control of therapeutic glycoproteins, which could be useful for the understanding of the development of therapeutic glycoproteins. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Specific and efficient gene delivery mediated by an asialofetuin-associated nanosystem.

    Science.gov (United States)

    Farinha, Dina; Pedroso de Lima, Maria C; Faneca, Henrique

    2014-10-01

    Gene therapy is considered a promising approach for the treatment of hepatocellular carcinoma (HCC). In this regard, the main goal of this work was to develop a specific and efficient gene delivery nanosystem to HCC based on 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine:cholesterol cationic liposomes and asialofetuin (ASF), a specific ligand to the asialoglycoprotein receptor (ASGP-R) that is overexpressed in HCC. Our results show that association of ASF to lipoplexes promotes a substantial increase in their biological activity in HCC cells, not only in vitro, but also in an animal model. The transfection activity obtained with this novel nanosystem (ASF-lipoplexes) was much higher than that observed with a highly efficient commercial formulation. On the other hand, the presence of high concentrations of galactose substantially reduced the cell uptake and biological activity of the ASF-lipoplexes. These results, together with those obtained in the presence of inhibitors of endocytosis, show that the potentiation induced by the association of ASF to lipoplexes is due to its specific interaction with the ASGP-R. The physicochemical properties of the generated nanosystem also reinforce this observation. Overall, our results demonstrate for the first time that the novel ASF-lipoplexes present a noticeable ability to specifically and efficiently deliver genetic material into HCC cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Diagnosis and Management of Autoimmune Hepatitis: Current Status and Future Directions

    Science.gov (United States)

    Czaja, Albert J.

    2016-01-01

    Autoimmune hepatitis is characterized by autoantibodies, hypergammaglobulinemia, and interface hepatitis on histological examination. The features lack diagnostic specificity, and other diseases that may resemble autoimmune hepatitis must be excluded. The clinical presentation may be acute, acute severe (fulminant), or asymptomatic; conventional autoantibodies may be absent; centrilobular necrosis and bile duct changes may be present; and the disease may occur after liver transplantation or with features that suggest overlapping disorders. The diagnostic criteria have been codified, and diagnostic scoring systems can support clinical judgment. Nonstandard autoantibodies, including antibodies to actin, α-actinin, soluble liver antigen, perinuclear antineutrophil antigen, asialoglycoprotein receptor, and liver cytosol type 1, are tools that can support the diagnosis, especially in patients with atypical features. Prednisone or prednisolone in combination with azathioprine is the preferred treatment, and strategies using these medications in various doses can ameliorate treatment failure, incomplete response, drug intolerance, and relapse after drug withdrawal. Budesonide, mycophenolate mofetil, and calcineurin inhibitors can be considered in selected patients as frontline or salvage therapies. Molecular (recombinant proteins and monoclonal antibodies), cellular (adoptive transfer and antigenic manipulation), and pharmacological (antioxidants, antifibrotics, and antiapoptotic agents) interventions constitute future directions in management. The evolving knowledge of the pathogenic pathways and the advances in technology promise new management algorithms. PMID:26934884

  7. Targetable Photoactivatable Drugs. 1. Synthesis Of Water-Soluble Galactosamine . Containing Polymeric Carriers Of Chlorin E6 And Their Photodynamic Effect On Plc Cells In Vitro

    Science.gov (United States)

    Krinick, N. L.; Rihova, B.; Ulbrich, K.; Andrade, J. D.; Andrade, J. D.; Kopecek, J.

    1989-03-01

    A copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-methacryloylglycine p-nitrophenyl ester (MA-Gly-ONp) was synthesized by radical precipitation copolymerization. Galactosamine was coupled to the polymer by reaction with the active ester side chains. The remaining p-nitrophenyl groups were converted to amine functionalities via a polymeranalogous reaction with an excess of ethylene diamine. Chlorin e6 was activated using a mixed anhydride method and subsequently bound to the modified side chains of the polymer. The photodynamic activity of the conjugate with galactosamine as the targeting moiety was tested in vitro on a human hepatoma cell line: PLC/PRF/5 (Alexander cells). It appears that the conjugate enters the cell interior by receptor mediated pinocytosis via the asialoglycoprotein receptors present on the surface of the PLC cells. Photoactivation of the chlorin containing conjugate with red light proved cytotoxic to the cells. Structure tests comparing the HPMA copolymer-galactosamine-chlorin e6 conjugate and a nontargetable HPMA copolymer-chlorin e6 conjugate, with comparable chlorin e6 content, indicate that the targeted conjugate is more biologically active.

  8. Targeting human liver cancer cells with lactobionic acid-G(4)-PAMAM-FITC sorafenib loaded dendrimers.

    Science.gov (United States)

    Iacobazzi, Rosa Maria; Porcelli, Letizia; Lopedota, Angela Assunta; Laquintana, Valentino; Lopalco, Antonio; Cutrignelli, Annalisa; Altamura, Emiliano; Di Fonte, Roberta; Azzariti, Amalia; Franco, Massimo; Denora, Nunzio

    2017-08-07

    Reported here is the synthesis and biological evaluation of the asialoglycoprotein receptor (ASGP-R) targeted fourth generation poliamidoamine dendrimer (G(4)-PAMAM) loaded with sorafenib. The ASGP-R targeted dendrimer was obtained by conjugation of Lactobionic acid (La) to the G(4)-PAMAM dendrimer, followed by acetylation (Ac) of the free amino groups in order to reduce the non-specific interactions with the cell membrane. Moreover, by additionally grafting fluorescein (FITC), it was easy to characterize the internalization pathway and the intracellular fate of the targeted dendrimer Ac-La-G(4)-PAMAM-FITC. In vitro experiments performed on HepG-2 and HLE cell lines, allowed to study the ability of the dendrimers to affect the cell vitality. Confocal microscopy and cytofluorimetric analysis confirmed higher binding and uptake ability of the Ac-La-G(4)-PAMAM-FITC dendrimer in well differentiated and ASGP-R expressing human liver cancer cell line HepG-2 compared non-expressing HLE cells. Ac-La-G(4)-PAMAM-FITC dendrimer loaded with sorafenib was stable and showed sustained sorafenib release. As evidenced by the cytotoxicity studies, sorafenib included in the dendrimer maintained its effectiveness, and was able to produce a longer lasting effect over the time compared to molar equivalent doses of free sorafenib. This new targeted dendrimer appears to be a suitable carrier for the delivery of sorafenib to liver cancer cells expressing ASGP-R. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Galactose-functionalized multi-responsive nanogels for hepatoma-targeted drug delivery

    Science.gov (United States)

    Lou, Shaofeng; Gao, Shan; Wang, Weiwei; Zhang, Mingming; Zhang, Ju; Wang, Chun; Li, Chen; Kong, Deling; Zhao, Qiang

    2015-02-01

    We report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-d-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using a combination of enzymatic transesterification and emulsion copolymerization for intracellular drug delivery. The nanogel exhibited redox, pH and temperature-responsive properties, which can be adjusted by varying the monomer feeding ratio. Furthermore, the volume phase transition temperature (VPTT) of the nanogels was close to body temperature and can result in rapid thermal gelation at 37 °C. Scanning electron microscopy also revealed that the P(ODGal-VCL-MAA) nanogel showed uniform spherical monodispersion. With pyrene as a probe, the fluorescence excitation spectra demonstrated nanogel degradation in response to glutathione (GSH). X-ray diffraction (XRD) showed an amorphous property of DOX within the nanogel, which was used in this study as a model anti-cancer drug. Drug-releasing characteristics of the nanogel were examined in vitro. The results showed multi-responsiveness of DOX release by the variation of environmental pH values, temperature or the availability of GSH, a biological reductase. An in vitro cytotoxicity assay showed a higher anti-tumor activity of the galactose-functionalized DOX-loaded nanogels against human hepatoma HepG2 cells, which was, at least in part, due to specific binding between the galactose segments and the asialoglycoprotein receptors (ASGP-Rs) in hepatic cells. Confocal laser scanning microscopy (CLSM) and flow cytometric profiles further confirmed elevated cellular uptake of DOX by the galactose-functionalised nanogels. Thus, we report here a multi-responsive P(ODGal-VCL-MAA) nanogel with a hepatoma-specific targeting ability for anti-cancer drug delivery.We report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-d-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using

  10. A galactose-functionalized dendritic siRNA-nanovector to potentiate hepatitis C inhibition in liver cells

    Science.gov (United States)

    Lakshminarayanan, Abirami; Reddy, B. Uma; Raghav, Nallani; Ravi, Vijay Kumar; Kumar, Anuj; Maiti, Prabal K.; Sood, A. K.; Jayaraman, N.; Das, Saumitra

    2015-10-01

    A RNAi based antiviral strategy holds the promise to impede hepatitis C viral (HCV) infection overcoming the problem of emergence of drug resistant variants, usually encountered in the interferon free direct-acting antiviral therapy. Targeted delivery of siRNA helps minimize adverse `off-target' effects and maximize the efficacy of therapeutic response. Herein, we report the delivery of siRNA against the conserved 5'-untranslated region (UTR) of HCV RNA using a liver-targeted dendritic nano-vector functionalized with a galactopyranoside ligand (DG). Physico-chemical characterization revealed finer details of complexation of DG with siRNA, whereas molecular dynamic simulations demonstrated sugar moieties projecting ``out'' in the complex. Preferential delivery of siRNA to the liver was achieved through a highly specific ligand-receptor interaction between dendritic galactose and the asialoglycoprotein receptor. The siRNA-DG complex exhibited perinuclear localization in liver cells and co-localization with viral proteins. The histopathological studies showed the systemic tolerance and biocompatibility of DG. Further, whole body imaging and immunohistochemistry studies confirmed the preferential delivery of the nucleic acid to mice liver. Significant decrease in HCV RNA levels (up to 75%) was achieved in HCV subgenomic replicon and full length HCV-JFH1 infectious cell culture systems. The multidisciplinary approach provides the `proof of concept' for restricted delivery of therapeutic siRNAs using a target oriented dendritic nano-vector.A RNAi based antiviral strategy holds the promise to impede hepatitis C viral (HCV) infection overcoming the problem of emergence of drug resistant variants, usually encountered in the interferon free direct-acting antiviral therapy. Targeted delivery of siRNA helps minimize adverse `off-target' effects and maximize the efficacy of therapeutic response. Herein, we report the delivery of siRNA against the conserved 5'-untranslated

  11. Assessment of the Drug Interaction Potential of Unconjugated and GalNAc3-Conjugated 2'-MOE-ASOs.

    Science.gov (United States)

    Shemesh, Colby S; Yu, Rosie Z; Warren, Mark S; Liu, Michael; Jahic, Mirza; Nichols, Brandon; Post, Noah; Lin, Song; Norris, Daniel A; Hurh, Eunju; Huang, Jane; Watanabe, Tanya; Henry, Scott P; Wang, Yanfeng

    2017-12-15

    Antisense oligonucleotides are metabolized by nucleases and drug interactions with small drug molecules at either the cytochrome P450 (CYP) enzyme or transporter levels have not been observed to date. Herein, a comprehensive in vitro assessment of the drug-drug interaction (DDI) potential was carried out with four 2'-O-(2-methoxyethyl)-modified antisense oligonucleotides (2'-MOE-ASOs), including a single triantennary N-acetyl galactosamine (GalNAc 3 )-conjugated ASO. Several investigations to describe the DDI potential of a 2'-MOE-ASO conjugated to a high-affinity ligand for hepatocyte-specific asialoglycoprotein receptors are explored. The inhibition on CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 and induction on CYP1A2, CYP2B6, and CYP3A4 were investigated in cryopreserved hepatocytes using up to 100 μM of each ASO. No significant inhibition (half maximal inhibitory concentration [IC 50 ] > 100 μM) or induction was observed based on either enzymatic phenotype or mRNA levels. In addition, transporter interaction studies were conducted with nine major transporters per recommendations from regulatory guidances and included three hepatic uptake transporters, organic cation transporter 1 (OCT1), organic anion transporting polypeptide 1B1 (OATP1B1), and OATP1B3; three renal uptake transporters, organic anion transporter 1 (OAT1), OAT3, and OCT2; and three efflux transporters, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and bile salt export pump (BSEP). None of the four ASOs (10 μM) were substrates of any of the nine transporters, with uptake drug molecules via any major CYP enzyme or drug transporters at clinically relevant exposures. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Diagnosis of abnormal biliary copper excretion by positron emission tomography with targeting of (64)Copper-asialofetuin complex in LEC rat model of Wilson's disease.

    Science.gov (United States)

    Bahde, Ralf; Kapoor, Sorabh; Bhargava, Kuldeep K; Palestro, Christopher J; Gupta, Sanjeev

    2014-01-01

    Identification by molecular imaging of key processes in handling of transition state metals, such as copper (Cu), will be of considerable clinical value. For instance, the ability to diagnose Wilson's disease with molecular imaging by identifying copper excretion in an ATP7B-dependent manner will be very significant. To develop highly effective diagnostic approaches, we hypothesized that targeting of radiocopper via the asialoglycoprotein receptor will be appropriate for positron emission tomography, and examined this approach in a rat model of Wilson's disease. After complexing (64)Cu to asialofetuin we studied handling of this complex compared with (64)Cu in healthy LEA rats and diseased homozygous LEC rats lacking ATP7B and exhibiting hepatic copper toxicosis. We analyzed radiotracer clearance from blood, organ uptake, and biliary excretion, including sixty minute dynamic positron emission tomography recordings. In LEA rats, (64)Cu-asialofetuin was better cleared from blood followed by liver uptake and greater biliary excretion than (64)Cu. In LEC rats, (64)Cu-asialofetuin activity cleared even more rapidly from blood followed by greater uptake in liver, but neither (64)Cu-asialofetuin nor (64)Cu appeared in bile. Image analysis demonstrated rapid visualization of liver after (64)Cu-asialofetuin administration followed by decreased liver activity in LEA rats while liver activity progressively increased in LEC rats. Image analysis resolved this difference in hepatic activity within one hour. We concluded that (64)Cu-asialofetuin complex was successfully targeted to the liver and radiocopper was then excreted into bile in an ATP7B-dependent manner. Therefore, hepatic targeting of radiocopper will be appropriate for improving molecular diagnosis and for developing drug/cell/gene therapies in Wilson's disease.

  13. Lactobionic acid-conjugated TPGS nanoparticles for enhancing therapeutic efficacy of etoposide against hepatocellular carcinoma

    Science.gov (United States)

    Tsend-Ayush, Altansukh; Zhu, Xiumei; Ding, Yu; Yao, Jianxu; Yin, Lifang; Zhou, Jianping; Yao, Jing

    2017-05-01

    Many effective anti-cancer drugs have limited use in hepatocellular carcinoma (HCC) therapy due to the drug resistance mechanisms in liver cells. In recent years, tumor-targeted drug delivery and the inhibition of drug-resistance-related mechanisms has become an integrated strategy for effectively combating chemo-resistant cancer. Herein, lactobionic acid-conjugated d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS-LA conjugate) has been developed as a potential asialoglycoprotein receptor (ASGPR)-targeted nanocarrier and an efficient inhibitor of P-glycoprotein (P-gp) to enhance etoposide (ETO) efficacy against HCC. The main properties of ETO-loaded TPGS-LA nanoparticles (NPs) were tested through in vitro and in vivo studies after being prepared using the nanoprecipitation method and characterized by dynamic light scattering (DLS). According to the results, smaller (∼141.43 nm), positively charged ETO-loaded TPGS-LA NPs were more suitable for providing efficient delivery to hepatoma cells by avoiding the clearance mechanisms. It was found that ETO-loaded TPGS-LA NPs were noticeably able to enhance the cytotoxicity of ETO in HepG2 cells. Besides this, markedly higher internalization by the ASGPR-overexpressed HepG2 cells and efficient accumulation at the tumor site in vivo were revealed in the TPGS-LA NP group. More importantly, animal studies confirmed that ETO-loaded TPGS-LA NPs achieved the highest therapeutic efficacy against HCC. Interestingly, ETO-loaded TPGS-LA NPs also exhibited a great inhibitory effect on P-gp compared to the ETO-loaded TPGS NPs. These results suggest that TPGS-LA NPs could be used as a potential ETO delivery system against HCC.

  14. Liver-targeting of interferon-alpha with tissue-specific domain antibodies.

    Directory of Open Access Journals (Sweden)

    Edward Coulstock

    Full Text Available Interferon alpha (IFNα is used for the treatment of hepatitis C infection and whilst efficacious it is associated with multiple adverse events including reduced leukocyte, erythrocyte, and platelet counts, fatigue, and depression. These events are most likely caused by systemic exposure to interferon. We therefore hypothesise that targeting the therapeutic directly to the intended site of action in the liver would reduce exposure in blood and peripheral tissue and hence improve the safety and tolerability of IFNα therapy. We genetically fused IFN to a domain antibody (dAb specific to a hepatocyte restricted antigen, asialoglycoprotein receptor (ASGPR. Our results show that the murine IFNα2 homolog (mIFNα2 fused to an ASGPR specific dAb, termed DOM26h-196-61, could be expressed in mammalian tissue culture systems and retains the desirable biophysical properties and activity of both fusion partners when measured in vitro. Furthermore a clear increase in in vivo targeting of the liver by mIFNα2-ASGPR dAb fusion protein, compared to that observed with either unfused mIFNα2 or mIFNα2 fused to an isotype control dAb VHD2 (which does not bind ASGPR was demonstrated using microSPECT imaging. We suggest that these findings may be applicable in the development of a liver-targeted human IFN molecule with improved safety and patient compliance in comparison to the current standard of care, which could ultimately be used as a treatment for human hepatitis virus infections.

  15. The FUT2 secretor variant p.Trp154Ter influences serum vitamin B12 concentration via holo-haptocorrin, but not holo-transcobalamin, and is associated with haptocorrin glycosylation.

    Science.gov (United States)

    Velkova, Aneliya; Diaz, Jennifer E L; Pangilinan, Faith; Molloy, Anne M; Mills, James L; Shane, Barry; Sanchez, Erica; Cunningham, Conal; McNulty, Helene; Cropp, Cheryl D; Bailey-Wilson, Joan E; Wilson, Alexander F; Brody, Lawrence C

    2017-12-15

    Vitamin B12 deficiency is common in older individuals. Circulating vitamin B12 concentration can be used to diagnose deficiency, but this test has substantial false positive and false negative rates. We conducted genome-wide association studies (GWAS) in which we resolved total serum vitamin B12 into the fractions bound to transcobalamin and haptocorrin: two carrier proteins with very different biological properties. We replicated reported associations between total circulating vitamin B12 concentrations and a common null variant in FUT2. This allele determines the secretor phenotype in which blood group antigens are found in non-blood body fluids. Vitamin B12 bound to haptocorrin (holoHC) remained highly associated with FUT2 rs601338 (p.Trp154Ter). Transcobalamin bound vitamin B12 (holoTC) was not influenced by this variant. HoloTC is the bioactive the form of the vitamin and is taken up by all tissues. In contrast, holoHC is only taken up by the liver. Using holoHC from individuals with known FUT2 genotypes, we demonstrated that FUT2 rs601338 genotype influences the glycosylation of haptocorrin. We then developed an experimental model demonstrating that holoHC is transported into cultured hepatic cells (HepG2) via the asialoglycoprotein receptor (ASGR). Our data challenge current published hypotheses on the influence of genetic variation on this clinically important measure and are consistent with a model in which FUT2 rs601338 influences holoHC by altering haptocorrin glycosylation, whereas B12 bound to non-glycosylated transcobalamin (i.e. holoTC) is not affected. Our findings explain some of the observed disparity between use of total B12 or holoTC as first-line clinical tests of vitamin B12 status. Published by Oxford University Press 2017. This work is written by US Government employees and is in the public domain in the US.

  16. Increased gene delivery efficiency and specificity of a lipid-based nanosystem incorporating a glycolipid.

    Science.gov (United States)

    Magalhães, Mariana; Farinha, Dina; Pedroso de Lima, Maria Conceição; Faneca, Henrique

    2014-01-01

    Hepatocellular carcinoma (HCC) is the third most common cause of death related to cancer diseases worldwide. The current treatment options have many limitations and reduced success rates. In this regard, advances in gene therapy have shown promising results in novel therapeutic strategies. However, the success of gene therapy depends on the efficient and specific delivery of genetic material into target cells. In this regard, the main goal of this work was to develop a new lipid-based nanosystem formulation containing the lipid lactosyl-PE for specific and efficient gene delivery into HCC cells. The obtained results showed that incorporation of 15% of lactosyl-PE into liposomes induces a strong potentiation of lipoplex biological activity in HepG2 cells, not only in terms of transgene expression levels but also in terms of percentage of transfected cells. In the presence of galactose, which competes with lactosyl-PE for the binding to the asialoglycoprotein receptor (ASGP-R), a significant reduction in biological activity was observed, showing that the potentiation of transfection induced by the presence of lactosyl-PE could be due to its specific interaction with ASGP-R, which is overexpressed in HCC. In addition, it was found that the incorporation of lactosyl-PE in the nanosystems promotes an increase in their cell binding and uptake. Regarding the physicochemical properties of lipoplexes, the presence of lactosyl-PE resulted in a significant increase in DNA protection and in a substantial decrease in their mean diameter and zeta potential, conferring them suitable characteristics for in vivo application. Overall, the results obtained in this study suggest that the potentiation of the biological activity induced by the presence of lactosyl-PE is due to its specific binding to the ASGP-R, showing that this novel formulation could constitute a new gene delivery nanosystem for application in therapeutic strategies in HCC.

  17. Octanoyl galactose ester-modified microemulsion system self-assembled by coix seed components to enhance tumor targeting and hepatoma therapy.

    Science.gov (United States)

    Qu, Ding; Liu, Mingjian; Huang, Mengmeng; Wang, Lixiang; Chen, Yan; Liu, Congyan; Liu, Yuping

    2017-01-01

    A nanosized drug delivery platform with a combination of rational components and tumor targeting is significant for enhancement of anticancer therapy and reduction of side effects. In this study, we developed a octanoyl galactose ester-modified microemulsion system self-assembled by coix seed components (Gal(oct)-C-MEs), which improved the tumor accumulation through asialoglycoprotein receptor-mediated endocytosis and promoted the antitumor efficacy through multicomponent-mediated synergistic effect. Octanoyl galactose ester (Gal(oct)) with a yield of 82.3% was synthesized through a green enzymatic reaction and multidimensional characterization. Gal(oct)-C-MEs with a spherical shape had a small and uniform particle size (58.49±1.03 nm), narrow polydispersity index (0.09±0.01) and neutral surface charge (-5.82±0.57 mV). In the cellular uptake studies, the internalized Gal(oct)-C-ME was 2.28-fold higher relative to that of coix seed component-based microemulsions (C-MEs). The half-maximal inhibitory concentration of Gal(oct)-C-MEs against HepG2 cells was 46.5±2.4 μg/mL, which was notably higher than that of C-MEs. Importantly, the intratumor fluorescence of HepG2 xenograft-bearing nude mice treated with Cy5/Gal(oct)-C-MEs was 1.9-fold higher relative to treatment with Cy5/C-MEs. In the study of antitumor efficacy in vivo, HepG2 xenograft-bearing nude mice intragastrically administered Gal(oct)-C-MEs for 14 days exhibited the strongest inhibition of tumor growth and the lowest toxicity against liver and kidney among all the treatments. In summary, Gal(oct)-C-ME, as a highly effective and safe anticancer drug delivery system, showed promising potential for hepatoma therapy.

  18. Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

    Directory of Open Access Journals (Sweden)

    Keiichi Motoyama

    2015-11-01

    Full Text Available The Niemann–Pick type C disease (NPC is one of inherited lysosomal storage disorders, emerges the accumulation of unesterified cholesterol in endolysosomes. Currently, 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD has been applied for the treatment of NPC. HP-β-CyD improved hepatosplenomegaly in NPC patients, however, a high dose of HP-β-CyD was necessary. Therefore, the decrease in dose by actively targeted-β-CyD to hepatocytes is expected. In the present study, to deliver β-CyD selectively to hepatocytes, we newly fabricated mono-lactose-appended β-CyD (Lac-β-CyD and evaluated its cholesterol lowering effects in NPC-like HepG2 cells, cholesterol accumulated HepG2 cells induced by treatment with U18666A. Lac-β-CyD (degree of substitution of lactose (DSL 1 significantly decreased the intracellular cholesterol content in a concentration-dependent manner. TRITC-Lac-β-CyD was associated with NPC-like HepG2 cells higher than TRITC-β-CyD. In addition, TRITC-Lac-β-CyD was partially localized with endolysosomes after endocytosis. Thus, Lac-β-CyD entered NPC-like HepG2 cells via asialoglycoprotein receptor (ASGPR-mediated endocytosis and decreased the accumulation of intracellular cholesterol in NPC-like HepG2 cells. These results suggest that Lac-β-CyD may have the potential as a drug for the treatment of hepatosplenomegaly in NPC disease.

  19. Targeted Sterically Stabilized Phospholipid siRNA Nanomedicine for Hepatic and Renal Fibrosis

    Directory of Open Access Journals (Sweden)

    Fatima Khaja

    2016-01-01

    Full Text Available Since its discovery, small interfering RNA (siRNA has been considered a potent tool for modulating gene expression. It has the ability to specifically target proteins via selective degradation of messenger RNA (mRNA not easily accessed by conventional drugs. Hence, RNA interference (RNAi therapeutics have great potential in the treatment of many diseases caused by faulty protein expression such as fibrosis and cancer. However, for clinical application siRNA faces a number of obstacles, such as poor in vivo stability, and off-target effects. Here we developed a unique targeted nanomedicine to tackle current siRNA delivery issues by formulating a biocompatible, biodegradable and relatively inexpensive nanocarrier of sterically stabilized phospholipid nanoparticles (SSLNPs. This nanocarrier is capable of incorporating siRNA in its core through self-association with a novel cationic lipid composed of naturally occuring phospholipids and amino acids. This overall assembly protects and delivers sufficient amounts of siRNA to knockdown over-expressed protein in target cells. The siRNA used in this study, targets connective tissue growth factor (CTGF, an important regulator of fibrosis in both hepatic and renal cells. Furthermore, asialoglycoprotein receptors are targeted by attaching the galactosamine ligand to the nanocarries which enhances the uptake of nanoparticles by hepatocytes and renal tubular epithelial cells, the major producers of CTGF in fibrosis. On animals this innovative nanoconstruct, small interfering RNA in sterically stabilized phospholipid nanoparticles (siRNA-SSLNP, showed favorable pharmacokinetic properties and accumulated mostly in hepatic and renal tissues making siRNA-SSLNP a suitable system for targeting liver and kidney fibrotic diseases.

  20. Elucidation of the Biotransformation Pathways of a Galnac3-conjugated Antisense Oligonucleotide in Rats and Monkeys

    Directory of Open Access Journals (Sweden)

    Colby S Shemesh

    2016-01-01

    Full Text Available Triantennary N-acetyl galactosamine (GalNAc3 is a high-affinity ligand for hepatocyte-specific asialoglycoprotein receptors. Conjugation with GalNAc3 via a trishexylamino (THA-C6 cluster significantly enhances antisense oligonucleotide (ASO potency. Herein, the biotransformation, disposition, and elimination of the THA cluster of ION-681257, a GalNAc3-conjugated ASO currently in clinical development, are investigated in rats and monkey. Rats were administered a single subcutaneous dose of 3H-radiolabeled (3H placed in THA or nonradiolabeled ION-681257. Mass balance included radiometric profiling and metabolite fractionation with characterization by mass spectrometry. GalNAc3-conjugated ASOs were extensively distributed into liver. The THA-C6 triantenerrary GalNAc3 conjugate at the 5′-end of the ASO was rapidly metabolized and excreted with 25.67 ± 1.635% and 71.66 ± 4.17% of radioactivity recovered in urine and feces within 48 hours postdose. Unchanged drug, short-mer ASOs, and linker metabolites were detected in urine. Collectively, 14 novel linker associated metabolites were discovered including oxidation at each branching arm, initially by monooxidation at the β-position followed by dioxidation at the α-arm, and lastly, tri and tetra oxidations on the two remaining β-arms. Metabolites in bile and feces were identical to urine except for oxidized linear and cyclic linker metabolites. Enzymatic reaction phenotyping confirmed involvement of N-acetyl-β-glucosaminidase, deoxyribonuclease II, alkaline phosphatase, and alcohol + aldehyde dehydrogenases on the complex metabolism pathway for THA supplementing in vivo findings. Lastly, excreta from monkeys treated with ION-681257 revealed the identical series as observed in rat. In summary, our findings provide an improved understanding of GalNAc3-conjugated-ASO metabolism pathways which facilitate similar development programs.

  1. Quantitative microscopy reveals 3D organization and kinetics of endocytosis in rat hepatocytes.

    Science.gov (United States)

    Marbet, Permsin; Rahner, Christoph; Stieger, Bruno; Landmann, Lukas

    2006-09-01

    In order to demonstrate the power of quantitative microscopy, the endocytic apparatus of rat hepatocytes was reexamined using in situ liver and short term cultured hepatocyte couplets that were allowed to internalize endocytic markers for various time intervals. Correlative confocal light and electron microscopy demonstrate a tubulovesicular reticulum representing the endocytic apparatus. Volume and membrane area account for 2% of cell volume and 30% plasma membrane surface. Colocalization analysis demonstrated that pathway-specific ligands and fluid-phase markers enter EEA1-positive vesicles, the early endosomal compartment, immediately after internalization. These vesicles are translocated rapidly from basolateral to perinuclear and apical locations. Ligands are sorted within 5 min to their respective pathways. Sequential colocalization of an asialoglycoprotein-pulse with rab7 and lamp3 demonstrates that early endosomes change into or fuse with late endosomes and lysosomes. Alternatively, markers are sequestered into the common endosome consisting of rab11-positive, long tubules that originate from early endosomes and show an affinity for the transcytotic marker pIgA and its receptor. This compartment mediates transcytosis by delivering the receptor-ligand complex to the subapical compartment, a set of apical, rab11-positive vesicles, which are connected to the tubular reticulum. We conclude that vesicular traffic between preexisting compartments, maturation or fusion of endocytic organelles, and transport in tubules act in concert and together mediate transport between compartments of a tubulovesicular endocytic apparatus. In addition, we show that quantitative microscopy using high resolution data sets can detect and characterize kinetics of various parameters thus adding a dynamic component to 3D information. (c) 2006 Wiley-Liss, Inc.

  2. Characterization of the hepatic disposition of lanoteplase, a rationally designed variant of tissue plasminogen activator in rodents.

    Science.gov (United States)

    Komoriya, Kazumi; Kato, Yukio; Hayashi, Yujiro; Ohsuye, Kazuhiro; Nishigaki, Ryuichiro; Sugiyama, Yuichi

    2007-03-01

    Lanoteplase is a recombinant mutant of tissue-type plasminogen activator (t-PA) that was developed with an aim to overcome the drawback of rapid systemic elimination of t-PA. In this study, we examined the disposition profile of lanoteplase in vivo and the kinetics of receptor-mediated endocytosis (RME) of this recombinant t-PA in vitro to kinetically characterize the mechanism(s) underlying its tissue distribution and elimination. Integration plot analysis of the initial-phase tissue distribution in rats revealed a much lower uptake clearance (CL(uptake)) of lanoteplase in the liver than that of t-PA. Rate constants for cell surface binding, internalization, and degradation of lanoteplase were also lower than those for t-PA in primary cultured rat hepatocytes. These results suggest that the improved stability of lanoteplase in vivo could be accounted for by the delay in the RME of this recombinant protein. The CL(uptake) in the liver decreased with coadministration of lactoferrin, a ligand for the low-density lipoprotein receptor-related protein (LRP) and the asialoglycoprotein (ASGP) receptors in normal mice, and in lrpap1((-/-)) mice, which have a hereditary deficiency of LRP; In contrast, CL(uptake) was not affected by mannose, whereas that of t-PA decreased with both ligands and in the lrpap1((-/-)) mice. Thus, the hepatic disposition of lanoteplase seems to be mediated by common specific receptors for t-PA, including LRP and the ASGP receptors, whereas the mannose receptor seems to be only minimally involved in the disposition of lanoteplase.

  3. Galactose-functionalized multi-responsive nanogels for hepatoma-targeted drug delivery.

    Science.gov (United States)

    Lou, Shaofeng; Gao, Shan; Wang, Weiwei; Zhang, Mingming; Zhang, Ju; Wang, Chun; Li, Chen; Kong, Deling; Zhao, Qiang

    2015-02-21

    We report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-D-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using a combination of enzymatic transesterification and emulsion copolymerization for intracellular drug delivery. The nanogel exhibited redox, pH and temperature-responsive properties, which can be adjusted by varying the monomer feeding ratio. Furthermore, the volume phase transition temperature (VPTT) of the nanogels was close to body temperature and can result in rapid thermal gelation at 37 °C. Scanning electron microscopy also revealed that the P(ODGal-VCL-MAA) nanogel showed uniform spherical monodispersion. With pyrene as a probe, the fluorescence excitation spectra demonstrated nanogel degradation in response to glutathione (GSH). X-ray diffraction (XRD) showed an amorphous property of DOX within the nanogel, which was used in this study as a model anti-cancer drug. Drug-releasing characteristics of the nanogel were examined in vitro. The results showed multi-responsiveness of DOX release by the variation of environmental pH values, temperature or the availability of GSH, a biological reductase. An in vitro cytotoxicity assay showed a higher anti-tumor activity of the galactose-functionalized DOX-loaded nanogels against human hepatoma HepG2 cells, which was, at least in part, due to specific binding between the galactose segments and the asialoglycoprotein receptors (ASGP-Rs) in hepatic cells. Confocal laser scanning microscopy (CLSM) and flow cytometric profiles further confirmed elevated cellular uptake of DOX by the galactose-functionalised nanogels. Thus, we report here a multi-responsive P(ODGal-VCL-MAA) nanogel with a hepatoma-specific targeting ability for anti-cancer drug delivery.

  4. Development of {sup 68}Ga-labelled DTPA galactosyl human serum albumin for liver function imaging

    Energy Technology Data Exchange (ETDEWEB)

    Haubner, Roland [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria); Medizinische Universitaet Innsbruck, Universitaetsklinik fuer Nuklearmedizin, Innsbruck (Austria); Vera, David R.; Farshchi-Heydari, Salman [University of California, Department of Radiology, School of Medicine, and the UCSD Molecular Imaging Program, San Diego, CA (United States); Helbok, Anna; Rangger, Christine; Putzer, Daniel; Virgolini, Irene J. [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria)

    2013-08-15

    The hepatic asialoglycoprotein receptor is responsible for degradation of desialylated glycoproteins through receptor-mediated endocytosis. It has been shown that imaging of the receptor density using [{sup 99m}Tc]diethylenetriamine pentaacetic acid (DTPA) galactosyl human serum albumin ([{sup 99m}Tc]GSA) allows non-invasive determination of functional hepatocellular mass. Here we present the synthesis and evaluation of [{sup 68}Ga]GSA for the potential use with positron emission tomography (PET). Labelling of GSA with {sup 68}Ga was carried out using a fractionated elution protocol. For quality control thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and size exclusion chromatography (SEC) techniques were evaluated. Stability of [{sup 68}Ga]GSA was studied in phosphate-buffered saline (PBS) and human serum. For in vivo evaluation [{sup 68}Ga]GSA distribution in Lewis rats was compared with [{sup 99m}Tc]GSA by using a dual isotope protocol. PET and planar imaging studies were performed using the same scaled molar dose of [{sup 68}Ga]GSA and [{sup 99m}Tc]GSA. Time-activity curves (TAC) for heart and liver were generated and corresponding parameters calculated (t50, t90). [{sup 68}Ga]GSA can be produced with high radiochemical purity. The best TLC methods for determining potential free {sup 68}Ga include 0.1 M sodium citrate as eluent. None of the TLC methods tested were able to determine potential colloids. This can be achieved by SEC. HPLC confirmed high radiochemical purity (>98 %). Stability after 120 min incubation at 37 C was high in PBS (>95 % intact tracer) and low in human serum ({proportional_to}27 % intact tracer). Biodistribution studies simultaneously injecting both tracers showed comparable liver uptake, whereas activity concentration in blood was higher for [{sup 68}Ga]GSA compared to [{sup 99m}Tc]GSA. The [{sup 99m}Tc]GSA TACs exhibited a small degree of hepatic metabolism compared to the [{sup 68}Ga]GSA curves. The mean

  5. Inhibition of hepatitis B virus and induction of hepatoma cell apoptosis by ASGPR-directed delivery of shRNAs.

    Directory of Open Access Journals (Sweden)

    Jingwei Ma

    Full Text Available Hepatitis B virus (HBV infection is a worldwide liver disease and nearly 25% of chronic HBV infections terminate in hepatocellular carcinoma (HCC. Currently, there is no effective therapy to inhibit HBV replication and to eliminate hepatoma cells, making it highly desired to develop novel therapies for these two stages of the HBV-caused detrimental disease. Recently, short hairpin RNA (shRNA has emerged as a potential therapy for virus-infected disease and cancer. Here, we have generated a shRNA, pGenesil-siHBV4, which effectively inhibits HBV replication in the human hepatoma cell line HepG2.2.15. The inhibitory effects of pGenesil-siHBV4 are manifested by the decrease of both the HBV mRNA level and the protein levels of the secreted HBV surface antigen (HBsAg and HBV e antigen (HBeAg, and by the reduction of secreted HBV DNA. Using mouse hydrodynamic tail vein injection, we demonstrate that pGenesil-siHBV4 is effective in inhibiting HBV replication in vivo. Because survivin plays a key role in cancer cell escape from apoptosis, we further generated pGenesil-siSurvivin, a survivin-silencing shRNA, and showed its effect of triggering apoptosis of HBV-containing hepatoma cells. To develop targeted shRNA therapy, we have identified that as a specific binder of the asialoglycoprotein receptor (ASGPR, jetPEI-Hepatocyte delivers pGenesil-siHBV4 and pGenesil-siSurvivin specifically to hepatocytes, not other types of cells. Finally, co-transfection of pGenesil-siHBV4 and pGenesil-siSurvivin exerts synergistic effects in inducing hepatoma cell apoptosis, a novel approach to eliminate hepatoma by downregulating survivin via multiple mechanisms. The application of these novel shRNAs with the jetPEI-Hepatocyte targeting strategy demonstrates the proof-of-principle for a promising approach to inhibit HBV replication and eliminate hepatoma cells with high specificity.

  6. Cell Penetrating Polymers Containing Guanidinium Trigger Apoptosis in Human Hepatocellular Carcinoma Cells unless Conjugated to a Targeting N-Acetyl-Galactosamine Block.

    Science.gov (United States)

    Tan, Zhe; Dhande, Yogesh K; Reineke, Theresa M

    2017-12-20

    A series of 3-guanidinopropyl methacrylamide (GPMA)-based polymeric gene delivery vehicles were developed via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers have been evaluated for their cellular internalization ability, transfection efficiency, and cytotoxicity. Two homopolymers: P(GPMA 20 ), P(GPMA 34 ), were synthesized to study the effect of guanidium polymer length on delivery efficiency and toxicity. In addition, an N-acetyl-d-galactosamine (GalNAc)-based hydrophilic block was incorporated to produce diblock polymers, which provides a neutral hydrophilic block that sterically protects plasmid-polymer complexes (polyplexes) from colloidal aggregation and aids polyplex targeting to hepatocytes via binding to asialoglycoprotein receptors (ASGPRs). Polyplexes formed with P(GPMA x ) (x = 20, 34) homopolymers were shown to be internalized via both energy-dependent and independent pathways, whereas polyplexes formed with block polymers were internalized through endocytosis. Notably, P(GPMA x ) polyplexes enter cells very efficiently but are also very toxic to human hepatocellular carcinoma (HepG2) cells and triggered cell apoptosis. In comparison, the presence of a carbohydrate block in the polymer structures reduced the cytotoxicity of the polyplex formulations and increased gene delivery efficiency with HepG2 cells. Transfection efficiency and toxicity studies were also carried out with HEK 293T (human embryonic kidney) cells for comparison. Results showed that polyplexes formed with the P(GPMA x ) homopolymers exhibit much higher transfection efficiency and lower toxicity with HEK 293T cells. The presence of the carbohydrate block did not further increase transfection efficiency in comparison to the homopolymers with HEK 293T cells, likely due to the lack of ASGPRs on the HEK 293T cell line. This study revealed that although guanidinium-based polymers have high membrane permeability, their application as plasmid

  7. Development of ⁶⁸Ga-labelled DTPA galactosyl human serum albumin for liver function imaging.

    Science.gov (United States)

    Haubner, Roland; Vera, David R; Farshchi-Heydari, Salman; Helbok, Anna; Rangger, Christine; Putzer, Daniel; Virgolini, Irene J

    2013-08-01

    The hepatic asialoglycoprotein receptor is responsible for degradation of desialylated glycoproteins through receptor-mediated endocytosis. It has been shown that imaging of the receptor density using [(99m)Tc]diethylenetriamine pentaacetic acid (DTPA) galactosyl human serum albumin ([(99m)Tc]GSA) allows non-invasive determination of functional hepatocellular mass. Here we present the synthesis and evaluation of [(68)Ga]GSA for the potential use with positron emission tomography (PET). Labelling of GSA with (68)Ga was carried out using a fractionated elution protocol. For quality control thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and size exclusion chromatography (SEC) techniques were evaluated. Stability of [(68)Ga]GSA was studied in phosphate-buffered saline (PBS) and human serum. For in vivo evaluation [(68)Ga]GSA distribution in Lewis rats was compared with [(99m)Tc]GSA by using a dual isotope protocol. PET and planar imaging studies were performed using the same scaled molar dose of [(68)Ga]GSA and [(99m)Tc]GSA. Time-activity curves (TAC) for heart and liver were generated and corresponding parameters calculated (t50, t90). [(68)Ga]GSA can be produced with high radiochemical purity. The best TLC methods for determining potential free (68)Ga include 0.1 M sodium citrate as eluent. None of the TLC methods tested were able to determine potential colloids. This can be achieved by SEC. HPLC confirmed high radiochemical purity (>98%). Stability after 120 min incubation at 37 °C was high in PBS (>95% intact tracer) and low in human serum (∼27% intact tracer). Biodistribution studies simultaneously injecting both tracers showed comparable liver uptake, whereas activity concentration in blood was higher for [(68)Ga]GSA compared to [(99m)Tc]GSA. The [(99m)Tc]GSA TACs exhibited a small degree of hepatic metabolism compared to the [(68)Ga]GSA curves. The mean [(68)Ga]GSA t90 was higher than the mean t90 for [(99m)Tc]GSA. The mean