| 1. |
- Gullberg, Elisabet, et al.
(författare)
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Yersinia pseudotuberculosis induces transcytosis of nanoparticles across human intestinal villus epithelium via invasin-dependent macropinocytosis
- 2008
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Ingår i: Laboratory investigation; a journal of technical methods and pathology. - New York, USA : Elsevier BV. - 1530-0307 .- 0023-6837. ; 88:11, s. 1215-26
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Tidskriftsartikel (refereegranskat)abstract
- Crohn's disease is characterized by a defect in intestinal barrier function, where bacteria are considered the most important inflammation-driving factor. Enteric bacteria, including E. coli and Yersinia spp, affect tight junctions in enterocytes, but little is known about bacterial effects on the transcellular pathway. Our objective was to study the short-term effects of Y. pseudotuberculosis on uptake of nanoparticles across human villus epithelium. Monolayers of human colon epithelium-derived Caco-2 cells and biopsies of normal human ileum were studied after 2 h exposure to Y. pseudotuberculosis expressing (inv+) or lacking (inv-) the bacterial adhesion molecule, invasin. Transepithelial transport of fluorescent nanoparticles (markers of transcytosis) was quantified by flow cytometry, and mechanisms explored by using inhibitors of endocytosis. Epithelial expressions of beta1-integrin and particle uptake pathways were studied by confocal microscopy. The paracellular pathway was assessed by electrical resistance (TER), mannitol flux, and expression of tight junction proteins occludin and caludin-4 by confocal microscopy. Inv+ Y. pseudotuberculosis adhered to the apical surface of epithelial cells and induced transcytosis of exogenous nanoparticles across Caco-2 monolayers (30-fold increase, P<0.01) and ileal mucosa (268+/-47% of control; P<0.01), whereas inv bacteria had no effect on transcytosis. The transcytosis was concentration-, particle size- and temperature-dependent, and possibly mediated via macropinocytosis. Y. pseudotuberculosis also induced apical expression of beta1-integrin on epithelial cells. A slight drop in TER was seen after exposure to inv+ Y. pseudotuberculosis, whereas mannitol flux and tight junction protein expression was unchanged. In summary, Y. pseudotuberculosis induced apical expression of beta1-integrin and stimulated uptake of nanoparticles via invasin-dependent transcytosis in human intestinal epithelium. Our findings suggest that bacterial factors may initiate transcytosis of luminal exogenous particles across human ileal mucosa, thus presenting a novel mechanism of intestinal barrier dysfunction.
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| 2. |
- Good, James A. D., 1985-, et al.
(författare)
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Thiazolino 2-Pyridone Amide Inhibitors of Chlamydia trachomatis Infectivity
- 2016
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 59:5, s. 2094-2108
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Tidskriftsartikel (refereegranskat)abstract
- The bacterial pathogen Chlamydia trachomatis is a global health burden currently treated with broad-spectrum antibiotics which disrupt commensal bacteria. We recently identified a compound through phenotypic screening that blocked infectivity of this intracellular pathogen without host cell toxicity (compound 1, KSK 120). Herein, we present the optimization of 1 to a class of thiazolino 2-pyridone amides that are highly efficacious (EC50 <= 100 nM) in attenuating infectivity across multiple serovars of C. trachomatis without host cell toxicity. The lead compound 21a exhibits reduced lipophilicity versus 1 and did not affect the growth or viability of representative commensal flora at 50 mu M. In microscopy studies, a highly active fluorescent analogue 37 localized inside the parasitiphorous inclusion, indicative of a specific targeting of bacterial components. In summary, we present a class of small molecules to enable the development of specific treatments for C. trachomatis.
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| 3. |
- Llona-Minguez, Sabin, et al.
(författare)
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Discovery of the First Potent and Selective Inhibitors of Human dCTP Pyrophosphatase 1
- 2016
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 59:3, s. 1140-1148
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Tidskriftsartikel (refereegranskat)abstract
- The dCTPase pyrophosphatase 1 (dCTPase) regulates the intracellular nucleotide pool through hydrolytic degradation of canonical and noncanonical nucleotide triphosphates (dNTPs). dCTPase is highly expressed in multiple carcinomas and is associated with cancer cell sternness. Here we report on the development of the first potent and selective dCTPase inhibitors that enhance the cytotoxic effect of cytidine analogues in leukemia cells. Boronate 30 displays a promising in vitro ADME profile, including plasma and mouse microsomal half-lives, aqueous solubility, cell permeability and CYP inhibition, deeming it a suitable compound for in vivo studies.
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| 4. |
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| 5. |
- Mateus, André, 1986-
(författare)
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Intracellular unbound drug concentrations : Methodology and application for understanding cellular drug exposure
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Most known drug targets and metabolizing enzymes are located inside cells. Interactions with these proteins are determined by intracellular unbound drug concentrations. Assessing intracellular drug exposure is technically challenging, but essential for predicting pharmacokinetic, pharmacological, and toxicological profiles of new drugs.This thesis aims at establishing and applying a straightforward methodology to measure intracellular unbound drug concentrations. This was achieved by separately measuring cellular drug binding (fu,cell), and total intracellular drug accumulation (Kp). This allowed the calculation of intracellular drug bioavailability (Fic), which represents the fraction of the concentration added to the cells that is unbound in the cell interior.The methodology was initially developed in HEK293 cells, where the Fic of 189 drug-like compounds was measured. Binding to HEK293 cells was governed by compound lipophilicity and was correlated with binding to more complex systems, such as hepatocytes and brain. Due to negligible expression of drug transporters, Fic in this cell line was consistent with pH-dependent subcellular sequestration of lipophilic cations in low pH compartments.The methodology was then applied to study the effects of drug transporters on Fic. The uptake transporter OATP1B1 increased the Fic of its substrates in a concentration-dependent manner. In contrast, the Fic of P-gp substrates was decreased when P-gp was present. In human hepatocytes, the methodology allowed the determination of Fic without prior knowledge of transporter mechanisms or metabolic activity.Finally, the methodology was applied to measure the impact of Fic on target binding and cellular drug response. Intracellular concentrations of active metabolites of pro-drugs targeting the intracellular target thymidylate synthase were in agreement with the level of binding to this target. Further, high Fic was generally required for kinase and protease inhibitors to be active in cellular assays.In conclusion, the methodology can be used to predict if new drug candidates reach their intracellular targets in sufficient amounts. Furthermore, the methodology can improve in vitro predictions of drug clearance and drug-drug interactions, by measuring the drug available for intracellular enzymes. Finally, this work can be expanded to other xenobiotics, e.g., to predict their intracellular toxicity.
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| 6. |
- Llona-Minguez, Sabin, et al.
(författare)
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Identification of Triazolothiadiazoles as Potent Inhibitors of the dCTP Pyrophosphatase 1
- 2017
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 60:5, s. 2148-2154
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Tidskriftsartikel (refereegranskat)abstract
- The dCTP pyrophosphatase 1 (dCTPase) is involved in the regulation of the cellular dNTP pool and has been linked to cancer progression. Here we report on the discovery of a series of 3,6-disubstituted triazolothiadiazoles as potent dCTPase inhibitors. Compounds 16 and 18 display good correlation between enzymatic inhibition and target engagement, together with efficacy in a cellular synergy model, deeming them as a promising starting point for hit -to-lead development.
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| 7. |
- Hovd, M., et al.
(författare)
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Neither Gastric Bypass Surgery Nor Diet-Induced Weight-Loss Affect OATP1B1 Activity as Measured by Rosuvastatin Oral Clearance
- 2023
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Ingår i: Clinical Pharmacokinetics. - : Springer Science and Business Media LLC. - 0312-5963 .- 1179-1926. ; 62:5, s. 725-735
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionRosuvastatin pharmacokinetics is mainly dependent on the activity of hepatic uptake transporter OATP1B1. In this study, we aimed to investigate and disentangle the effect of Roux-en-Y gastric bypass (RYGB) and weight loss on oral clearance (CL/F) of rosuvastatin as a measure of OATP1B1-activity.MethodsPatients with severe obesity preparing for RYGB (n = 40) or diet-induced weight loss (n = 40) were included and followed for 2 years, with four 24-hour pharmacokinetic investigations. Both groups underwent a 3-week low-energy diet (LED; < 1200 kcal/day), followed by RYGB or a 6-week very-low-energy diet (VLED; < 800 kcal/day).ResultsA total of 80 patients were included in the RYGB group (40 patients) and diet-group (40 patients). The weight loss was similar between the groups following LED and RYGB. The LED induced a similar (mean [95% CI]) decrease in CL/F in both intervention groups (RYGB: 16% [0, 31], diet: 23% [8, 38]), but neither induced VLED resulted in any further changes in CL/F. At Year 2, CL/F had increased by 21% from baseline in the RYGB group, while it was unaltered in the diet group. Patients expressing the reduced function SLCO1B1 variants (c.521TC/CC) showed similar changes in CL/F over time compared with patients expressing the wild-type variant.ConclusionsNeither body weight, weight loss nor RYGB per se seem to affect OATP1B1 activity to a clinically relevant degree. Overall, the observed changes in rosuvastatin pharmacokinetics were minor, and unlikely to be of clinical relevance.
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| 8. |
- Bose, Partha Pratim, et al.
(författare)
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In vitro ADMET and physicochemical investigations of poly-N-methylated peptides designed to inhibit Aβ aggregation
- 2010
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 18:16, s. 5896-5902
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Tidskriftsartikel (refereegranskat)abstract
- N-Methylation is a common strategy for improving oral bioavailability of peptide-based lead structures. Herein, we present a detailed study on how the degree of N-methylation affects the absorption-distribution-metabolism-excretion-toxicity (ADMET) properties such as solubility, membrane transport, proteolytic stability, and general cell toxicity of the investigated peptides. As representative structures we chose hexapeptides 1-8. These peptides, corresponding to N-methylated analogues of residues 16-21 and 32-37 of the Abeta-peptide, pathological hallmark of Alzheimer's disease (AD), have previously been shown to inhibit aggregation of Abeta fibrils in vitro. This study suggests that poly-N-methylated peptides are non-toxic and have enhanced proteolytic stability over their non-methylated analogues. Furthermore, solubility in aqueous solution is seen to increase with increased degree of N-methylation, while membrane transport was found to be low for all investigated hexapeptides. The present results, together with those reported in the literature, suggest that poly-N-methylated peptides, especially shorter or equal to six residues, can be suitable candidates for drug design.
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| 9. |
- Caraballo, Remi, et al.
(författare)
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Structure-activity relationships for lipoprotein lipase agonists that lower plasma triglycerides in vivo
- 2015
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier. - 0223-5234 .- 1768-3254. ; 103, s. 191-209
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Tidskriftsartikel (refereegranskat)abstract
- The risk of cardiovascular events increases in individuals with elevated plasma triglyceride (TG) levels, therefore advocating the need for efficient TG-lowering drugs. In the blood circulation, TG levels are regulated by lipoprotein lipase (LPL), an unstable enzyme that is only active as a non-covalently associated homodimer. We recently reported on a N-phenylphthalimide derivative (1) that stabilizes LPL in vitro, and moderately lowers triglycerides in vivo (Biochem. Biophys. Res. Common. 2014, 450, 1063). Herein, we establish structure activity relationships of 51 N-phenylphthalimide analogs of the screening hit 1. In vitro evaluation highlighted that modifications on the phthalimide moiety were not tolerated and that lipophilic substituents on the central phenyl ring were functionally essential. The substitution pattern on the central phenyl ring also proved important to stabilize LPL However, in vitro testing demonstrated rapid degradation of the phthalimide fragment in plasma which was addressed by replacing the phthalimide scaffold with other heterocyclic fragments. The in vitro potency was retained or improved and substance 80 proved stable in plasma and efficiently lowered plasma TGs in vivo. 2015 The Authors. Published by Elsevier Masson SAS.
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| 10. |
- Gullberg, Elisabet, et al.
(författare)
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Identification of Cell Adhesion Molecules in the Human Follicle-Associated Epithelium That Improve Nanoparticle Uptake into the Peyer's Patches
- 2006
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 319:2, s. 632-639
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to identify cell adhesion molecules that could serve as targets of the human follicle-associated epithelium (FAE) overlying Peyer's patches and to assess nanoparticle uptake levels across this epithelium. We first studied the expression of the mouse M-cell marker beta(1)-integrin and used a model of human FAE derived from intestinal epithelial Caco-2 cells and Raji B-cells to identify additional potential targets by cDNA array. The protein expression of potential targets in the model FAE and in human ileal FAE tissues was quantified by immunofluorescence. Integrin targeting was studied by investigating the transport of Arg-Gly-Asp (RGD)-coated (integrin- binding), Arg-Gly-Glu (RGE)-coated (nonintegrin-binding), and uncoated nanoparticles across ileal specimens mounted in Ussing chambers. Both beta(1)-integrin and the cell adhesion molecule CD9 were more abundantly expressed in the model and human FAE compared with the Caco-2 control cells or villus epithelium (VE). Uncoated nanoparticles were not taken up across either FAE or VE. General integrin targeting with RGD improved the nanoparticle transport dramatically across the FAE and to a lower extent across the VE. Compared with RGE, RGD improved transport 4-fold across the FAE. There was no difference in the transport of RGD- and RGE-coated nanoparticles across the VE. In conclusion, beta(1)-integrin and CD9 were identified as targets in human FAE. The difference in RGD- and RGE-mediated transport across the FAE, but not the VE, suggests that a specific integrin interaction was the dominating mechanism for improved nanoparticle uptake across the FAE., whereas charge interaction contributed substantially to the improved VE uptake.
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