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Springer AD, Dowdy SF. GalNAc-siRNA Conjugates: Leading the Way for Delivery of RNAi Therapeutics. Nucleic Acid Ther 2018; 28:109-118. [PMID: 29792572 PMCID: PMC5994659 DOI: 10.1089/nat.2018.0736] [Citation(s) in RCA: 381] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 12/15/2022] Open
Abstract
Short-interfering RNA (siRNA)-induced RNAi responses have great potential to treat a wide variety of human diseases from cancer to pandemic viral outbreaks to Parkinson's Disease. However, before siRNAs can become drugs, they must overcome a billion years of evolutionary defenses designed to keep invading RNAs on the outside cells from getting to the inside of cells. Not surprisingly, significant effort has been placed in developing a wide array of delivery technologies. Foremost of these has been the development of N-acetylgalactosamine (GalNAc) siRNA conjugates for delivery to liver. Tris-GalNAc binds to the Asialoglycoprotein receptor that is highly expressed on hepatocytes resulting in rapid endocytosis. While the exact mechanism of escape across the endosomal lipid bilayer membrane remains unknown, sufficient amounts of siRNAs enter the cytoplasm to induce robust, target selective RNAi responses in vivo. Multiple GalNAc-siRNA conjugate clinical trials, including two phase III trials, are currently underway by three biotech companies to treat a wide variety of diseases. GalNAc-siRNA conjugates are a simple solution to the siRNA delivery problem for liver hepatocytes and have shown the RNAi (and antisense oligonucleotide) field the path forward for targeting other tissue types.
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Affiliation(s)
- Aaron D Springer
- Department of Cellular and Molecular Medicine, University of California San Diego , La Jolla, California
| | - Steven F Dowdy
- Department of Cellular and Molecular Medicine, University of California San Diego , La Jolla, California
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Yuan L, Wang J, Shen WC. Reversible lipidization of somatostatin analogues for the liver targeting. Eur J Pharm Biopharm 2008; 70:615-20. [PMID: 18614343 DOI: 10.1016/j.ejpb.2008.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 04/30/2008] [Accepted: 05/05/2008] [Indexed: 10/22/2022]
Abstract
Tyr(3)-octreotide (TOC), a somatostatin analogue, is reversibly lipidized for passive delivery to the liver with the aim of increasing its association with hepatocytes. The reversibly lipidized TOC (REAL-TOC) was formed by the conjugation of the N-palmitoyl cysteinyl moiety to the cysteinyl residues of reduced TOC through disulfide linkages and characterized by matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF) analysis. The measured mass of REAL-TOC (M+H)(+) is 1752.31 Da (calculated mass: 1752.78), confirming that two molecules of N-palmitoyl cysteines are linked to TOC via disulfide bonds. TOC and REAL-TOC were radioiodinated and administered to mice. Their biodistribution and intrahepatic distribution were subsequently investigated. The area under the curve (AUC) of (125)I-REAL-TOC in the liver was 3.8-fold greater than that of (125)I-TOC, with 20.5% and 5.8% of the injected dose (ID)/g of (125)I-REAL-TOC remaining in the liver at 2 and 24h post injection, respectively. Within the liver, TOC was primarily distributed to parenchymal cells (PC). Nevertheless, TOC was quickly excreted out and only 2.4% ID per 100mg protein remained in the PC at 2h post injection. (125)I-REAL-TOC was retained in PC for up to 2h with a constant concentration of around 6% ID/100mg protein. (125)I-REAL-TOC was also highly associated with nonparenchymal cells (NPC) at significantly higher levels than (125)I-TOC at 10min, 1h and 2h post injection. Since somatostatin analogues have been evaluated for treating late-stage hepatocellular carcinoma (HCC), the reversibly lipidized conjugates may possess enhanced therapeutic efficacy due to the liver-targeting effect.
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Affiliation(s)
- Liyun Yuan
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
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Kelley JL. Chapter 12. Antiviral Agents. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2008; 19:117-126. [PMID: 32336813 PMCID: PMC7172521 DOI: 10.1016/s0065-7743(08)60688-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 03/29/2024]
Abstract
This chapter discusses the agents with activity primarily against RNA viruses. The communicable diseases of the respiratory tract are probably the most common cause of symptomatic human infections. The viruses that are causative agents for human respiratory disease comprise the five taxonomically distinct families: orthomyxoviridae, paramyxoviridae, picornaviridae, coronaviridae, and adenoviridae. The influenza viruses, which consist of types A, B, and C, belong to the family orthomyxoviridae. Types A and B have been associated with significant increases in mortality during epidemics. The disease may be asymptomatic or cause symptoms ranging from the common cold to fatal pneumonia. Immunization against influenza has been recommended for high-risk groups and antiviral chemotherapy (amantadine) is available for the treatment and prophylaxis of all influenza A infections. There is both a great need for and interest in developing a chemotherapeutic agent for the treatment of these two viral, respiratory tract pathogens. The family picornaviridae contains the genus Rhinovirus that is composed of over a hundred distinct serotypes. Amantadine and rimantadine are specifically active against influenza A virus infections. The amantadine recipients reported a higher incidence of side effects largely attributed to the central nervous system (CNS) symptoms. This difference in side effects may be a pharmacokinetic phenomenon that results in higher plasma concentrations of amantadine. Significant progress continues to be made in the clinical use and development of agents active against DNA viruses. Acyclovir (9-(2-h droxyethoxymethyl)guanine) has been the subject of several reviews and of a syrnposium. Considerable progress has been made in evaluating the clinical promise of acyclovir; however, there remains much to be learned concerning the best use of this drug in clinical practice. Significant strides have been made in the development of clinically useful antiviral agents, especially against the DNA viruses of the herpes family. Most of these agents are directed against viral nucleic acid synthesis and require activation by a virus-induced thymidine kinase. Researchers have begun to focus on other strategies that may produce broader spectrum anti-viral agents with different mechanisms of action.
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Affiliation(s)
- James L Kelley
- Wellcome Research Laboratories, Burroughs Wellcome Co. Research Triangle Park, NC 27709
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Gabius HJ. Glycohistochemistry: the why and how of detection and localization of endogenous lectins. Anat Histol Embryol 2001; 30:3-31. [PMID: 11284160 DOI: 10.1046/j.1439-0264.2001.00305.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The central dogma of molecular biology limits the downstream flow of genetic information to proteins. Progress from the last two decades of research on cellular glycoconjugates justifies adding the enzymatic production of glycan antennae with information-bearing determinants to this famous and basic pathway. An impressive variety of regulatory processes including cell growth and apoptosis, folding and routing of glycoproteins and cell adhesion/migration have been unravelled and found to be mediated or modulated by specific protein (lectin)-carbohydrate interactions. The conclusion has emerged that it would have meant missing manifold opportunities not to recruit the sugar code to cellular information transfer. Currently, the potential for medical applications in anti-adhesion therapy or drug targeting is one of the major driving forces fuelling progress in glycosciences. In histochemistry, this concept has prompted the introduction of carrier-immobilized carbohydrate ligands (neoglycoconjugates) to visualize the cells' capacity to be engaged in oligosaccharide recognition. After their isolation these tissue lectins will be tested for ligand analysis. Since fine specificities of different lectins can differ despite identical monosaccharide binding, the tissue lectins will eventually replace plant agglutinins to move from glycan profiling and localization to functional considerations. Namely, these two marker types, i.e. neoglycoconjugates and tissue lectins, track down accessible binding sites with relevance for involvement in interactions in situ. The documented interplay of synthetic organic chemistry and biochemistry with cyto- and histochemistry nourishes the optimism that the application of this set of innovative custom-prepared tools will provide important insights into the ways in which glycans can act as hardware in transmitting information during normal tissue development and pathological situations.
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Affiliation(s)
- H J Gabius
- Institut für Physiologische Chemie, Tierärztliche Fakultät, Ludwig-Maximilians-Universität München, Veterinärstr. 13, D-80539 München, Germany.
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Beljaars L, Poelstra K, Molema G, Meijer DK. Targeting of sugar- and charge-modified albumins to fibrotic rat livers: the accessibility of hepatic cells after chronic bile duct ligation. J Hepatol 1998; 29:579-88. [PMID: 9824267 DOI: 10.1016/s0168-8278(98)80153-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS In normal rat livers, cell-selective delivery of drugs to hepatocytes, endothelial cells and Kupffer cells can be achieved by coupling drugs to lactosaminated human serum albumin (lacHSA), succinylated HSA (sucHSA) and mannosylated HSA (manHSA), respectively. Since fibrosis is associated with increased matrix deposition and sinusoidal capillarization, and since these modified albumins may serve as carriers for anti-fibrotic drugs, we determined the hepatic disposition of these albumins in rats with liver fibrosis. METHODS At different time points after bile duct ligation, a bolus dose of either lacHSA, sucHSA or manHSA (fluorescein labelled) was intravenously injected and pharmacokinetic parameters were determined. Organ distributions of the 125I-labelled carriers were assessed in normal and fibrotic rats. In addition, their intrahepatic distributions were determined by immunohistochemical inspection. RESULTS In rats with liver fibrosis, the plasma disappearance rate of the three proteins was significantly altered as compared to control rats. A moderately decreased clearance for lacHSA, an increased plasma clearance for manHSA and sucHSA, and an increased volume of distribution for all three proteins was found. Despite these pharmacokinetic alterations, tissue distribution studies still showed selective accumulation of the three modified proteins in livers of diseased animals. Moreover, the intrahepatic distribution of these drug-carriers during fibrosis was similar to distribution in normal livers. CONCLUSIONS This study demonstrates that cell-specific delivery of sugar- and charge-modified albumins in fibrotic livers is possible. Despite the increased matrix deposition during fibrosis, the accessibility of the different liver cell types for the carriers was not significantly altered as compared to normal livers. The availability of a complete set of carriers for the different liver cell types provides opportunities for the development of effective therapeutic strategies based on drug targeting.
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Affiliation(s)
- L Beljaars
- Groningen Utrecht Institute for Drug Exploration, Department of Pharmacokinetics and Drug Delivery, University of Groningen, The Netherlands.
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Sato H, Sugiyama Y, Tsuji A, Horikoshi I. Importance of receptor-mediated endocytosis in peptide delivery and targeting: kinetic aspects. Adv Drug Deliv Rev 1996. [DOI: 10.1016/0169-409x(96)00013-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Monroe RS, Huber BE. The major form of the murine asialoglycoprotein receptor: cDNA sequence and expression in liver, testis and epididymis. Gene 1994; 148:237-44. [PMID: 7958950 DOI: 10.1016/0378-1119(94)90694-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Northern blot analysis of poly(A)+RNAs isolated from mouse liver or mouse testis (Te)/epididymis (Ep) reveals that both tissues express 1.5- and 7.5-kb transcripts which have extensive homology to the major form of the rat asialoglyco-protein receptor (ASGP-R). In situ hybridization studies have localized the expression of this ASGP-R-like transcript to late-stage sperm from Te and Ep of several different strains of mice. Swiss Webster mice express this ASGP-R-like transcript in late-stage spermatids at the time of release into the seminiferous tubule and in Ep sperm, while Balb/C, NIH Swiss and C57Bl/6 mice express this ASGP-R-like transcript predominantly in Ep sperm. cDNAs containing the entire coding region for this ASGP-R-like transcript have been cloned from mouse liver and mouse Te/Ep. These cDNAs are 100% identical in the coding region and 3'-untranslated region (UTR), but differ in the 5'-UTR. The gene encoding these cDNAs is called MHL-1, designating the major form of the mouse ASGP-R. The deduced amino acid (aa) sequence of MHL-1 shares 88% homology to the rat hepatic (He) lectin form 1 (RHL-1) and 78% homology to the human asialoglycoprotein receptor form 1 (H1). The three sites for N-linked glycosylation in the RHL-1 sequence are all conserved in the deduced MHL-1 sequence. Taken collectively, these data describe the cloning and sequencing of the MHL-1 cDNA and illustrate its deduced aa homology to RHL-1 and H1.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R S Monroe
- Wellcome Research Laboratories, Research Triangle Park, NC 27709
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Polichetti A, Viti V, Barone P, Colonna F, Fiume L. Prony-Householder method applied to 31P NMR signals: II. Study of conjugates of ara-AMP with lactosaminated albumin. Phys Med Biol 1992; 37:2231-42. [PMID: 1281919 DOI: 10.1088/0031-9155/37/12/005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Conjugates of 9-beta-D-arabinofuranosyladenine 5'-monophosphate (ara-AMP) with lactosaminated albumin (L-SA), obtained by using two different coupling procedures, produce antibodies in rats and mice which display only a small cross-reactivity. 31P NMR signals from the two conjugates have been examined to clarify whether different lysine and histidine residues are involved in the two reaction pathways. The occurrence of different chemical shifts and linewidths between the two conjugates, as evidenced by processing the signals with the Prony-Householder method, indicates the formation of two different complexes.
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Affiliation(s)
- A Polichetti
- Laboratorio di Fisica, Istituto Superiore di Sanità, Roma, Italy
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Affiliation(s)
- P G Canonico
- Southern Research Institute-Frederick Research Center, Maryland 21701
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Müller R, Klein H, Vido I, Niehoff G, Lautz HU, Gebel M, Schmidt FW. Antiviral treatment in chronic hepatitis B. Data of 5 prospectively controlled randomized trials. J Hepatol 1986; 3 Suppl 2:S217-23. [PMID: 2439573 DOI: 10.1016/s0168-8278(86)80123-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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A study on the pharmacokinetics in mouse of adenine-9-beta-D-arabinofuranoside 5-monophosphate conjugated with lactosaminated albumin. EXPERIENTIA 1985; 41:1326-8. [PMID: 2412878 DOI: 10.1007/bf01952078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In plasma of mice injected with adenine-9-beta-D-arabinofuranoside monophosphate (ara-AMP) coupled to human lactosaminated serum albumin (L-HSA) some of the ara-AMP molecules are enzymatically released, whereas others remain linked to L-HSA. Evidence has been obtained that ara-AMP is not deaminated when it is conjugated to L-HSA, in contrast to the free drug which is rapidly metabolized to its hypoxanthine derivative.
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Abstract
Several potent and selective antiviral agents against herpes virus infections have been developed. However, the majority of compounds against other viral diseases has not yet reached such high standard. Based on progress in molecular virology it can, however, be anticipated that similar concepts of selective inhibition will also be developed for other virus groups. In addition to virus-induced enzymes, viral proteins other than enzymes with specific activities will be identified. The identification of active sites will lead to the design of new and specific inhibitors. Moreover, studies on the mode of action of the huge number of known antiviral compounds may provide the basis for new and potent approaches to specific virus chemotherapy. New inhibitors of viral replication may also be derived from 2'-5'A and other mediators of the interferon induced antiviral state. However, since 2'-5'A does not enter cells, is rapidly degraded by phosphodiesterases, and affects viral and cellular protein synthesis, only analogs which do not have these disadvantages may qualify as antiviral drugs. In addition to refinements at the molecular level quantitative assays for a better evaluation of antiviral agents for clinical use are required. For clinical trials, rapid diagnosis, early initiation of treatment, and quantitative evaluation of the antiviral effects of a drug need to be developed. Moreover, new methods of drug delivery and/or drug targeting will improve potency and selectivity of antiviral compounds. Drug carriers have already successfully been used in cancer therapy (Poste and Fidler, 1981) they should be also applicable to virus chemotherapy. Finally, a better understanding of the pathogenesis and the natural course of viral diseases will contribute to the development of more effective and safe antiviral agents.
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Fiume L, Mattioli A, Busi C, Accorsi C. Selective penetration and pharmacological activity of lactosaminated albumin conjugates of adenine arabinoside 5-monophosphate (ara-AMP) in mouse liver. Gut 1984; 25:1392-8. [PMID: 6210232 PMCID: PMC1420207 DOI: 10.1136/gut.25.12.1392] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
With the aim of improving the chemotherapeutic index of adenine arabinoside 5-monophosphate (ara-AMP) in the treatment of chronic hepatitis B, this drug was conjugated with lactosaminated serum albumin (L-SA), a neoglycoprotein which only enters into hepatocytes where it is digested in lysosomes. In mice, the L-[3H]SA-ara-AMP conjugates, intravenously injected, selectively penetrated the liver, only small quantities were taken up by cells of spleen, bone marrow, intestine, and brain. After administration of the conjugate to mice with Ectromelia virus hepatitis, ara-AMP was selectively concentrated in liver in a pharmacologically active form. If L-SA-ara-AMP conjugates behave in man as in mouse, their administration to patients with chronic hepatitis B should result in a selective concentration of ara-AMP in liver with a more efficient inhibition of virus replication accompanied by lower toxicity for other tissues.
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