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Song KH. Effect of Tight Junction-Modulating FCIGRL-Modified Peptides on the Intestinal Absorption of Doxorubicin in Rats. Pharmaceutics 2024; 16:650. [PMID: 38794312 PMCID: PMC11125019 DOI: 10.3390/pharmaceutics16050650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Doxorubicin is a potent chemotherapy drug, but its oral bioavailability is limited due to its low membrane permeability. Thus, absorption enhancers such as zonula occludens toxin and its six-mer fragment, FCIGRL, have been studied to address this issue. This study aimed to evaluate the effectiveness of four peptides (Pep1, Pep2, Pep3, and Pep4) derived from FCIGRL and investigate the changes in the absorption of doxorubicin, to propose an absorption enhancer for doxorubicin. Pep1 is a modified version of FCIGRL in which the hydroxyl group at the C-terminus is replaced with an amino group. Pep2 is a modified Pep1 in which cysteine is replaced with N3-substituted dipropionic acid. Pep3 and Pep4 are Pep2-modified homodimers. Pharmacokinetic analysis was performed in rats after the intraduodenal administration of doxorubicin solutions containing each FCIGRL-modified peptide and the stabilizer levan or benzalkonium chloride (BC). The results showed that Pep3 and Pep4 administered with levan each significantly increased the intestinal absorption of doxorubicin, as did Pep2 administered with levan/BC. In particular, 10 mg·kg-1 of Pep4 with levan significantly increased the area under the curve (AUC)0-240min of doxorubicin by 2.38-fold (p < 0.01) and the peak concentration (Cmax) by 3.30-fold (p < 0.01) compared to the control solution. The study findings indicate that Pep2, Pep3, and primarily Pep4 are novel absorption enhancers that can open tight junctions for doxorubicin, and the effectiveness of the peptides was directly affected by the presence of levan or levan/BC.
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Affiliation(s)
- Keon-Hyoung Song
- Department of Pharmaceutical Engineering, College of Medical Sciences, Soonchunhyang University, Asan 31538, Republic of Korea
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2
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Pursuing Orally Bioavailable Hepcidin Analogues via Cyclic N-Methylated Mini-Hepcidins. Biomedicines 2021; 9:biomedicines9020164. [PMID: 33567510 PMCID: PMC7915682 DOI: 10.3390/biomedicines9020164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/20/2021] [Accepted: 02/02/2021] [Indexed: 11/20/2022] Open
Abstract
The peptide hormone hepcidin is one of the key regulators of iron absorption, plasma iron levels, and tissue iron distribution. Hepcidin functions by binding to and inducing the internalisation and subsequent lysosomal degradation of ferroportin, which reduces both iron absorption in the gut and export of iron from storage to ultimately decrease systemic iron levels. The key interaction motif in hepcidin has been localised to the highly conserved N-terminal region, comprising the first nine amino acid residues, and has led to the development of mini-hepcidin analogs that induce ferroportin internalisation and have improved drug-like properties. In this work, we have investigated the use of head-to-tail cyclisation and N-methylation of mini-hepcidin as a strategy to increase oral bioavailability by reducing proteolytic degradation and enhancing membrane permeability. We found that backbone cyclisation and N-methylation was well-tolerated in the mini-hepcidin analogues, with the macrocylic analogues often surpassing their linear counterparts in potency. Both macrocyclisation and backbone N-methylation were found to improve the stability of the mini-hepcidins, however, there was no effect on membrane-permeabilizing activity.
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Walke S, Srivastava G, Routaray CB, Dhavale D, Pai K, Doshi J, Kumar R, Doshi P. Preparation and characterization of microencapsulated DwPT trivalent vaccine using water soluble chitosan and its in-vitro and in-vivo immunological properties. Int J Biol Macromol 2017; 107:2044-2056. [PMID: 29037872 DOI: 10.1016/j.ijbiomac.2017.10.073] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/28/2017] [Accepted: 10/12/2017] [Indexed: 02/05/2023]
Abstract
The paper explained the microencapsulation of three different antigenic materials viz. Diphtheria toxoid (DT), whole cell pertussis antigens (PT and FHA) and tetanus toxoid (TT) by coacervation method using water soluble chitosan as a polymer crosslinked by vanillin/TPP co-crosslinkers for the development of oral trivalent DwPT vaccine. Instrumental characterization of chitosan microspheres suggested specific interaction with vanillin/TPP, higher thermal stability, amorphous nature, spherical morphology with size less than 2μm along with positive charge density offering mucoadhesive properties. Furthermore, PT and FHA showed higher encapsulation up to 94% followed by TT and DT. Cumulative release rate of DT was (68.47%), TT (73.67%), PT (43%) and FHA (53%). Release kinetics interpreted using DD solver program, indicated protein release followed first order kinetics and obeyed Korsmeyer-peppas model, stating fickian diffusion relates to diffusion, erosion and controlled release rate of the encapsulated toxoids. Application of formulations on caco-2 cell line showed negligible cytotoxic effect and efficient uptake of FITC labelled microspheres. The obtained in-vivo results suggests that the final trivalent DwPT formulation were having successful elicitation of both systemic (IgG) and mucosal (sIgA) immune response in balb/c mice. Overall studies indicated that DwPT formulation could be a suitable alternative to available injectable DaPT vaccine.
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Affiliation(s)
- Shilratna Walke
- Biochemistry Division, Department of Chemistry, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India
| | - Gopal Srivastava
- Biochemistry Division, Department of Chemistry, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India
| | - Chinmayee Bar Routaray
- Department of Zoology, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India
| | - Dilip Dhavale
- Biochemistry Division, Department of Chemistry, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India
| | - Kalpana Pai
- Department of Zoology, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India
| | - Jignesh Doshi
- Toxoid Purification Department, Serum Institute of India Ltd., Hadapsar, Pune-411028, India
| | - Rakesh Kumar
- Toxoid Purification Department, Serum Institute of India Ltd., Hadapsar, Pune-411028, India
| | - Pooja Doshi
- Biochemistry Division, Department of Chemistry, Savitribai Phule Pune University (Formerly Pune University), Pune-411 007, India.
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Song KH, Kim SB, Shim CK, Chung SJ, Kim DD, Rhee SK, Choi GJ, Kim CH, Kim K. Paracellular permeation-enhancing effect of AT1002 C-terminal amidation in nasal delivery. Drug Des Devel Ther 2015; 9:1815-23. [PMID: 25848218 PMCID: PMC4383222 DOI: 10.2147/dddt.s79383] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The identification of permeation enhancers has gained interest in the development of drug delivery systems. A six-mer peptide, H-FCIGRL-OH (AT1002), is a tight junction modulator with promising permeation-enhancing activity. AT1002 enhances the transport of molecular weight markers or agents with low bioavailability with no cytotoxicity. However, AT1002 is not stable in neutral pH or after incubation under physiological conditions, which is necessary to fully uncover its permeation-enhancing effect. Thus, we increased the stability or mitigated the instability of AT1002 by modifying its terminal amino acids and evaluated its subsequent biological activity. METHODS C-terminal-amidated (FCIGRL-NH2, Pep1) and N-terminal-acetylated (Ac-FCIGRL, Pep2) peptides were analyzed by liquid chromatography-mass spectrometry. We further assessed cytotoxicity on cell monolayers, as well as the permeation-enhancing activity following nasal administration of the paracellular marker mannitol. RESULTS Pep1 was nontoxic to cell monolayers and showed a relatively low decrease in peak area compared to AT1002. In addition, administration of mannitol with Pep1 resulted in significant increases in the area under the plasma concentration-time curve and peak plasma concentration at 3.63-fold and 2.68-fold, respectively, compared to mannitol alone. In contrast, no increase in mannitol concentration was shown with mannitol/AT1002 or mannitol/Pep2 compared to the control. Thus, Pep1 increased the stability or possibly reduced the instability of AT1002, which resulted in an increased permeation-enhancing effect of AT1002. CONCLUSION These results suggest the potential usefulness of C-terminal-amidated AT1002 in enhancing nasal drug delivery, which may lead to the development of a practical drug delivery technology for drugs with low bioavailability.
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Affiliation(s)
- Keon-Hyoung Song
- Department of Pharmaceutical Engineering, Soonchunhyang University, Asan, Republic of Korea
| | - Sang-Bum Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Chang-Koo Shim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Suk-Jae Chung
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Dae-Duk Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sang-Ki Rhee
- Department of Pharmaceutical Engineering, Soonchunhyang University, Asan, Republic of Korea
| | - Guang J Choi
- Department of Pharmaceutical Engineering, Soonchunhyang University, Asan, Republic of Korea
| | - Chul-Hyun Kim
- Department of Sports Medicine, Soonchunhyang University, Asan, Republic of Korea
| | - Kiyoung Kim
- Department of Medical Biotechnology, Soonchunhyang University, Asan, Republic of Korea
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Renukuntla J, Vadlapudi AD, Patel A, Boddu SHS, Mitra AK. Approaches for enhancing oral bioavailability of peptides and proteins. Int J Pharm 2013; 447:75-93. [PMID: 23428883 DOI: 10.1016/j.ijpharm.2013.02.030] [Citation(s) in RCA: 399] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/28/2012] [Accepted: 02/12/2013] [Indexed: 12/20/2022]
Abstract
Oral delivery of peptide and protein drugs faces immense challenge partially due to the gastrointestinal (GI) environment. In spite of considerable efforts by industrial and academic laboratories, no major breakthrough in the effective oral delivery of polypeptides and proteins has been accomplished. Upon oral administration, gastrointestinal epithelium acts as a physical and biochemical barrier for absorption of proteins resulting in low bioavailability (typically less than 1-2%). An ideal oral drug delivery system should be capable of (a) maintaining the integrity of protein molecules until it reaches the site of absorption, (b) releasing the drug at the target absorption site, where the delivery system appends to that site by virtue of specific interaction, and (c) retaining inside the gastrointestinal tract irrespective of its transitory constraints. Various technologies have been explored to overcome the problems associated with the oral delivery of macromolecules such as insulin, gonadotropin-releasing hormones, calcitonin, human growth factor, vaccines, enkephalins, and interferons, all of which met with limited success. This review article intends to summarize the physiological barriers to oral delivery of peptides and proteins and novel pharmaceutical approaches to circumvent these barriers and enhance oral bioavailability of these macromolecules.
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Affiliation(s)
- Jwala Renukuntla
- Division of Pharmaceutical Sciences, South College School of Pharmacy, 400 Goody's Lane, Knoxville, TN 37931, USA
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Lemmer HJR, Hamman JH. Paracellular drug absorption enhancement through tight junction modulation. Expert Opin Drug Deliv 2012; 10:103-14. [DOI: 10.1517/17425247.2013.745509] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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7
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Santos S, Torcato I, Castanho MARB. Biomedical applications of dipeptides and tripeptides. Biopolymers 2012. [DOI: 10.1002/bip.22067] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Paukner S, Kohl G, Jalava K, Lubitz W. Sealed Bacterial Ghosts—Novel Targeting Vehicles for Advanced Drug Delivery of Water-soluble Substances. J Drug Target 2010. [DOI: 10.3109/10611860310001593366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Jain AK, Goyal AK, Mishra N, Vaidya B, Mangal S, Vyas SP. PEG–PLA–PEG block copolymeric nanoparticles for oral immunization against hepatitis B. Int J Pharm 2010; 387:253-62. [DOI: 10.1016/j.ijpharm.2009.12.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2009] [Revised: 12/03/2009] [Accepted: 12/04/2009] [Indexed: 10/20/2022]
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10
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Biron E, Chatterjee J, Ovadia O, Langenegger D, Brueggen J, Hoyer D, Schmid HA, Jelinek R, Gilon C, Hoffman A, Kessler H. Improving oral bioavailability of peptides by multiple N-methylation: somatostatin analogues. Angew Chem Int Ed Engl 2008; 47:2595-9. [PMID: 18297660 DOI: 10.1002/anie.200705797] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Eric Biron
- CIPS at Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747-Garching, Germany
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Biron E, Chatterjee J, Ovadia O, Langenegger D, Brueggen J, Hoyer D, Schmid H, Jelinek R, Gilon C, Hoffman A, Kessler H. Die Verbesserung der oralen Bioverfügbarkeit von Peptiden durch multiple N-Methylierung: Somatostatin-Analoga. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200705797] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Hess S, Ovadia O, Shalev DE, Senderovich H, Qadri B, Yehezkel T, Salitra Y, Sheynis T, Jelinek R, Gilon C, Hoffman A. Effect of structural and conformation modifications, including backbone cyclization, of hydrophilic hexapeptides on their intestinal permeability and enzymatic stability. J Med Chem 2007; 50:6201-11. [PMID: 17983214 DOI: 10.1021/jm070836d] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A library of 18 hexapeptide analogs was synthesized, including sub-libraries of N- or C-methylation of the parent hexapeptide Phe-Gly-Gly-Gly-Gly-Phe, as well as backbone cyclized analogs of each linear analog with various ring sizes. N- or C-methylation as well as cyclization (but not backbone cyclization) have been suggested to improve intestinal permeability and metabolic stability of peptides in general. Here we aimed to assess their applicability to hydrophilic peptides. The intestinal permeability (Papp) of the 18-peptide library was in the range of 0.2-6.8 x 10-6 cm/sec. Based on several tests, we concluded that the absorption mechanism of all tested analogs is paracellular, regardless of the structural or conformational modifications. In all cases, backbone cyclization increased Papp (5-fold) in comparison to the linear analogs due to the smaller 3D size and also dramatically decreased peptide proteolysis by brush border enzymes. N- or C-methylation did not enhance the permeability of the linear analogs in this series.
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Affiliation(s)
- Shmuel Hess
- Departments of Pharmaceutics and Organic Chemistry, and the Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel
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Maher S, Feighery L, Brayden DJ, McClean S. Melittin as an epithelial permeability enhancer I: investigation of its mechanism of action in Caco-2 monolayers. Pharm Res 2007; 24:1336-45. [PMID: 17373574 DOI: 10.1007/s11095-007-9288-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 01/19/2007] [Indexed: 02/07/2023]
Abstract
PURPOSE Melittin is an amphipathic antimicrobial peptide which has been shown to enhance the permeability of mannitol and reduce transepithelial electrical resistance (TER) across Caco-2 monolayers. The aim of this work was to further examine the potential of melittin as a paracellular permeability enhancer and to investigate the mechanism of interaction with tight junction proteins in Caco-2. MATERIALS AND METHODS The permeability of a range of fluorescent markers of differing molecular weights across monolayers was examined and immunofluorescence and western blotting analysis of tight junction proteins were also carried out. The mechanism of TER reduction was also examined using cell signalling inhibitors. RESULTS Apical but not basolateral addition of melittin increased the permeability of a range FITC-dextrans (4-70 kDa) across monolayers. Melittin effects were reversible and no cytotoxicity was evident in polarized Caco-2 epithelia at the concentrations used. Altered expression of ZO-1, E-cadherin and F-actin was also detected. The phospholipase A2 inhibitors, aristolochic acid and indomethacin and the cyclooxygenase inhibitor, piroxicam, partially attenuated melittin-induced TER reduction, suggesting that part of the mechanism by which melittin opens tight junctions involves prostaglandin signalling. CONCLUSIONS Apically-added melittin opens tight junctions, causing dramatic TER reductions with significant increases in flux of dextrans. These effects appear mediated in part via PLA2 and involve alterations in specific tight junction proteins.
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Affiliation(s)
- Sam Maher
- Institute of Technology Tallaght Dublin, Belgard Road, Tallaght, Dublin, Ireland
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Branski D, Fasano A, Troncone R. Latest developments in the pathogenesis and treatment of celiac disease. J Pediatr 2006; 149:295-300. [PMID: 16939736 DOI: 10.1016/j.jpeds.2006.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 05/05/2006] [Accepted: 06/05/2006] [Indexed: 01/01/2023]
Affiliation(s)
- David Branski
- Department of Pediatrics, Hadassah University Hospitals, Hadassah Medical Organization, 91120 Jerusalem, Israel.
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des Rieux A, Fievez V, Garinot M, Schneider YJ, Préat V. Nanoparticles as potential oral delivery systems of proteins and vaccines: a mechanistic approach. J Control Release 2006; 116:1-27. [PMID: 17050027 DOI: 10.1016/j.jconrel.2006.08.013] [Citation(s) in RCA: 793] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Accepted: 08/08/2006] [Indexed: 12/15/2022]
Abstract
Peptides and proteins remain poorly bioavailable upon oral administration. One of the most promising strategies to improve their oral delivery relies on their association with colloidal carriers, e.g. polymeric nanoparticles, stable in gastrointestinal tract, protective for encapsulated substances and able to modulate physicochemical characteristics, drug release and biological behavior. The mechanisms of transport of these nanoparticles across intestinal mucosa are reviewed. In particular, the influence of size and surface properties on their non-specific uptake or their targeted uptake by enterocytes and/or M cells is discussed. Enhancement of their uptake by appropriate cells, i.e. M cells by (i) modeling surface properties to optimize access to and transport by M cells (ii) identifying surface markers specific to human M cell allowing targeting to M cells and nanoparticles transcytosis is illustrated. Encouraging results upon in vivo testing are reported but low bioavailability and lack of control on absorbed dose slow down products development. Vaccines are certainly the most promising applications for orally delivered nanoparticles.
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Affiliation(s)
- Anne des Rieux
- Université Catholique de Louvain, Unité de Pharmacie Galénique, Avenue E. Mounier, 73-20, 1200 Brussels, Belgium
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Drago S, El Asmar R, Di Pierro M, Grazia Clemente M, Tripathi A, Sapone A, Thakar M, Iacono G, Carroccio A, D'Agate C, Not T, Zampini L, Catassi C, Fasano A. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scand J Gastroenterol 2006; 41:408-19. [PMID: 16635908 DOI: 10.1080/00365520500235334] [Citation(s) in RCA: 317] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. MATERIAL AND METHODS Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression was evaluated by real-time polymerase chain reaction (PCR). RESULTS When exposed to gliadin, zonulin receptor-positive IEC6 and Caco2 cells released zonulin in the cell medium with subsequent zonulin binding to the cell surface, rearrangement of the cell cytoskeleton, loss of occludin-ZO1 protein-protein interaction, and increased monolayer permeability. Pretreatment with the zonulin antagonist FZI/0 blocked these changes without affecting zonulin release. When exposed to luminal gliadin, intestinal biopsies from celiac patients in remission expressed a sustained luminal zonulin release and increase in intestinal permeability that was blocked by FZI/0 pretreatment. Conversely, biopsies from non-celiac patients demonstrated a limited, transient zonulin release which was paralleled by an increase in intestinal permeability that never reached the level of permeability seen in celiac disease (CD) tissues. Chronic gliadin exposure caused down-regulation of both ZO-1 and occludin gene expression. CONCLUSIONS Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.
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Affiliation(s)
- Sandro Drago
- Mucosal Biology Research Center, Center for Celiac Research and Division of Pediatric Gastroenterology and Nutrition, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
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17
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Salamat-Miller N, Johnston TP. Current strategies used to enhance the paracellular transport of therapeutic polypeptides across the intestinal epithelium. Int J Pharm 2005; 294:201-16. [PMID: 15814245 DOI: 10.1016/j.ijpharm.2005.01.022] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Revised: 01/12/2005] [Accepted: 01/27/2005] [Indexed: 11/26/2022]
Abstract
The intent of this paper is to update the reader on various strategies which have been utilized to increase the paracellular permeability of protein and polypeptide drugs across the intestinal epithelium. Structural features of protein and polypeptide drugs, together with the natural anatomical and physiological features of the gastrointestinal (GI) tract, have made oral delivery of this class of compounds extremely challenging. Interest in the paracellular route for the transport of therapeutic proteins and polypeptides following oral administration has recently intensified and continues to be explored. The assumption that molecules with a large molecular weight are not able to diffuse through the tight junctions of the intestinal membrane has been challenged by current research, along with an increased understanding of tight junction physiology.
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Affiliation(s)
- Nazila Salamat-Miller
- Division of Pharmaceutical Sciences, Room 211A, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64110-2499, USA
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18
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Broughman JR, Brandt RM, Hastings C, Iwamoto T, Tomich JM, Schultz BD. Channel-forming peptide modulates transepithelial electrical conductance and solute permeability. Am J Physiol Cell Physiol 2004; 286:C1312-23. [PMID: 15151917 DOI: 10.1152/ajpcell.00426.2002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NC-1059, a synthetic channel-forming peptide, transiently increases transepithelial electrical conductance (g(TE)) and ion transport (as indicated by short-circuit current) across Madin-Darby canine kidney (MDCK) cell monolayers in a time- and concentration-dependent manner when apically exposed. g(TE) increases from <2 to >40 mS/cm(2) over the low to middle micromolar range. Dextran polymer (9.5 but not 77 kDa) permeates the monolayer following apical NC-1059 exposure, suggesting that modulation of the paracellular pathway accounts for changes in g(TE). However, concomitant alterations in junctional protein localization (zonula occludens-1, occludin) and cellular morphology are not observed. Effects of NC-1059 on MDCK g(TE) occur in nominally Cl(-)- and Na(+)-free apical media, indicating that permeation by these ions is not required for effects on g(TE), although two-electrode voltage-clamp assays with Xenopus oocytes suggest that both Cl(-) and Na(+) permeate NC-1059 channels with a modest Cl(-) permselectivity (P(Cl):P(Na) = 1.3). MDCK monolayers can be exposed to multiple NC-1059 treatments over days to weeks without diminution of response, alteration in the time course, or loss of responsiveness to physiological and pharmacological secretagogues. Together, these results suggest that NC-1059 represents a valuable tool to investigate tight junction regulation and may be a lead compound for therapeutic interventions.
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Affiliation(s)
- James R Broughman
- Department of Anatomy and Physiology, 228 Coles Hall, Kansas State University, Manhattan, KS 66506, USA
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Abstract
The intestine constitutes the largest interface between a person and his or her environment, and an intact intestinal barrier is thus essential in maintaining health and preventing tissue injury and several diseases. The intestinal barrier has various immunological and non-immunological components. The epithelial barrier is one of the most important non-immunological components. Hyperpermeability of this barrier is believed to contribute to the pathogenesis of several gastrointestinal disorders including inflammatory bowel disease, celiac disease and food allergy. Hence, assessing barrier integrity is of the utmost importance. One of the more quantitative gauges for this assessment is transepithelial permeability of various molecular probes, among which sugars are commonly used. Measures of intestinal permeability might also be useful as markers for assessment of prognosis and follow up in various gastrointestinal disorders. The present article is a review of the normal and abnormal functioning of the intestinal barrier, the diseases that can result from loss of barrier integrity, and some promising agents and strategies for restoring barrier normality and integrity.
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Affiliation(s)
- Ashkan Farhadi
- Department of Internal Medicine (Section of Gastroenterology and Nutrition), Rush University Medical Center, Chicago, Illinois 60612, USA.
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El Asmar R, Panigrahi P, Bamford P, Berti I, Not T, Coppa GV, Catassi C, Fasano A, El Asmar R. Host-dependent zonulin secretion causes the impairment of the small intestine barrier function after bacterial exposure. Gastroenterology 2002; 123:1607-15. [PMID: 12404235 DOI: 10.1053/gast.2002.36578] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Enteric infections have been implicated in the pathogenesis of both food intolerance and autoimmune diseases secondary to the impairment of the intestinal barrier. On the basis of our recent discovery of zonulin, a modulator of small-intestinal tight junctions, we asked whether microorganisms might induce zonulin secretion and increased small-intestinal permeability. METHODS Both ex vivo mammalian small intestines and intestinal cell monolayers were exposed to either pathogenic or nonpathogenic enterobacteria. Zonulin production and changes in paracellular permeability were monitored in Ussing chambers and micro-snapwells. Zonula occludens 1 protein redistribution after bacteria colonization was evaluated on cell monolayers. RESULTS Small intestines exposed to enteric bacteria secreted zonulin. This secretion was independent of either the species of the small intestines or the virulence of the microorganisms tested, occurred only on the luminal aspect of the bacteria-exposed small-intestinal mucosa, and was followed by a decrease in small-intestinal tissue resistance (transepithelial electrical resistance). The transepithelial electrical resistance decrement was secondary to the zonulin-induced tight junction disassembly, as also shown by the disengagement of the protein zonula occludens 1 protein from the tight junctional complex. CONCLUSIONS This zonulin-driven opening of the paracellular pathway may represent a defensive mechanism, which flushes out microorganisms and contributes to the host response against bacterial colonization of the small intestine.
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Affiliation(s)
- Ramzi El Asmar
- Department of Pediatrics and Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Abstract
Rapid development in molecular biology and recent advancement in recombinant technology increase identification and commercialization of potential protein drugs. Traditional forms of administrations for the peptide and protein drugs often rely on their parenteral injection, since the bioavailability of these therapeutic agents is poor when administered nonparenterally. Tremendous efforts by numerous investigators in the world have been put to improve protein formulations and as a result, a few successful formulations have been developed including sustained-release human growth hormone. For a promising protein delivery technology, efficacy and safety are the first requirement to meet. However, these systems still require periodic injection and increase the incidence of patient compliance. The development of an oral dosage form that improves the absorption of peptide and especially protein drugs is the most desirable formulation but one of the greatest challenges in the pharmaceutical field. The major barriers to developing oral formulations for peptides and proteins are metabolic enzymes and impermeable mucosal tissues in the intestine. Furthermore, chemical and conformational instability of protein drugs is not a small issue in protein pharmaceuticals. Conventional pharmaceutical approaches to address these barriers, which have been successful with traditional organic drug molecules, have not been effective for peptide and protein formulations. It is likely that effective oral formulations for peptides and proteins will remain highly compound specific. A number of innovative oral drug delivery approaches have been recently developed, including the drug entrapment within small vesicles or their passage through the intestinal paracellular pathway. This review provides a summary of the novel approaches currently in progress in the protein oral delivery followed by factors affecting protein oral absorption.
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Affiliation(s)
- Hye J Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Kwanak-Gu, Korea.
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Ramanathan S, Qiu B, Pooyan S, Zhang G, Stein S, Leibowitz MJ, Sinko PJ. Targeted PEG-based bioconjugates enhance the cellular uptake and transport of a HIV-1 TAT nonapeptide. J Control Release 2001; 77:199-212. [PMID: 11733088 DOI: 10.1016/s0168-3659(01)00474-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We previously described the enhanced cell uptake and transport of R.I-K(biotin)-Tat9, a large ( approximately 1500 Da) peptidic inhibitor of HIV-1 Tat protein, via SMVT, the intestinal biotin transporter. The aim of the present study was to investigate the feasibility of targeting biotinylated PEG-based conjugates to SMVT in order to enhance cell uptake and transport of Tat9. The 29 kDa peptide-loaded bioconjugate (PEG:(R.I-Cys-K(biotin)-Tat9)8) used in these studies contained eight copies of R.I-K(biotin)-Tat9 appended to PEG by means of a cysteine linkage. The absorptive transport of biotin-PEG-3400 (0.6-100 microM) and the bioconjugate (0.1-30 microM) was studied using Caco-2 cell monolayers. Inhibition of biotin-PEG-3400 by positive controls (biotin, biocytin, and desthiobiotin) was also determined. Uptake of these two compounds was also determined in CHO cells transfected with human SMVT (CHO/hSMVT) and control cells (CHO/pSPORT) over the concentration ranges of 0.05-12.5 microM and 0.003-30 microM, respectively. Nonbiotinylated forms of these two compounds, PEG-3350 and PEG:(R.I-Cys-K-Tat9)8, were used in the control studies. Biotin-PEG-3400 transport was found to be concentration-dependent and saturable in Caco-2 cells (K(m)=6.61 microM) and CHO/hSMVT cells (K(m)=1.26 microM). Transport/uptake was significantly inhibited by positive control substrates of SMVT. PEG:(R.I-Cys-K(biotin)Tat9)8 also showed saturable transport kinetics in Caco-2 cells (K(m)=6.13 microM) and CHO/hSMVT cells (K(m)=8.19 microM). Maximal uptake in molar equivalents of R.I-Cys-K(biotin)Tat9 was 5.7 times greater using the conjugate versus the biotinylated peptide alone. Transport of the nonbiotinylated forms was significantly lower (P<0.001) in all cases. The present results demonstrate that biotin-PEG-3400 and PEG:(R.I-Cys-K(biotin)Tat9)8 interact with human SMVT to enhance the cellular uptake and transport of these larger molecules and that targeted bioconjugates may have potential for enhancing the cellular uptake and transport of small peptide therapeutic agents.
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Affiliation(s)
- S Ramanathan
- College of Pharmacy, Rutgers-The State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
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Vines RR, Perdue SS, Moncrief JS, Sentz DR, Barroso LA, Wright RL, Wilkins TD. Fragilysin, the enterotoxin from Bacteroides fragilis, enhances the serum antibody response to antigen co-administered by the intranasal route. Vaccine 2000; 19:655-60. [PMID: 11090718 DOI: 10.1016/s0264-410x(00)00254-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fragilysin, an extracellular zinc metalloprotease produced by enterotoxigenic strains of the anaerobic bacterium Bacteroides fragilis, disrupts the paracellular barrier by cleavage of the intercellular proteins between epithelial cells resulting in fluid secretion. Intranasal immunization of mice with fragilysin and co-administered ovalbumin (Ova) resulted in an Ova-specific serum IgG response that was over 18000-fold higher than Ova alone, as well as detectable levels of serum IgA. Serum IgG titers were comparable with those seen when whole cholera toxin was used as the adjuvant, although the responses obtained with fragilysin showed more variability between mice. Metalloproteases to which fragilysin is structurally related were ineffective as mucosal adjuvants. Our results and similar studies with enterotoxins that affect the paracellular barrier suggest that alteration of mucosal permeability may play an important role in the mechanisms of adjuvanticity.
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Affiliation(s)
- R R Vines
- Department of Biochemistry, Fralin Biotechnology Center, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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Abstract
AIM: To investigate the interaction of Zot with microtubule.
METHODS: Zot affinity column was applied to purify Zot-binding protein(s) from crude intestinal cell lysates. After incubation at room temperature, the column was washed and the proteins bound to the Zot affinity column we re eluted by step gradient with NaCl (0.3-0.5 mol·L-1). The fractions were subjected to 6.0%-15.0% (w/v) gradient SDS-PAGE and then transferred to PVDF membrane for N-terminal sequencing. Purified Zot and tau protein were blotted by using anti-Zot or anti-tau antibodies. Finally, purified Zot was tested in an in vitro tubulin binding assay.
RESULTS: Fractions from Zot affinity column yielded two protein bands with a Mr of 60 kU and 45 kU respectively. The N-terminal sequence of the 60 kU band resulted identical to β-tubulin. Zot also cross-reacts with anti-tau antibodies. In the in vitro tubulin binding assay, Zot co-precipitate with Mt, further suggesting that Zot possesses tubulin-b inding properties.
CONCLUSION: Taken together, these results suggest that Zot regulates the permeability of intestinal tight junctions by binding to intracellular Mt, with the subsequent activation of the intracellular signaling leading to the permeabilization of intercellular tight junctions.
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Fasano A. Cellular microbiology: can we learn cell physiology from microorganisms? THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:C765-76. [PMID: 10199806 DOI: 10.1152/ajpcell.1999.276.4.c765] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular microbiology is a new discipline that is emerging at the interface between cell biology and microbiology. The application of molecular techniques to the study of bacterial pathogenesis has made possible discoveries that are changing the way scientists view the bacterium-host interaction. Today, research on the molecular basis of the pathogenesis of infective diarrheal diseases of necessity transcends established boundaries between cell biology, bacteriology, intestinal pathophysiology, and immunology. The use of microbial pathogens to address questions in cell physiology is just now yielding promising applications and striking results.
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Affiliation(s)
- A Fasano
- Department of Pediatrics and Physiology, and Gastrointestinal Pathophysiology Section, Center for Vaccine Development, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA.
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