| 1. |
- Laettig-Tuennemann, Gisela, et al.
(författare)
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Backbone rigidity and static presentation of guanidinium groups increases cellular uptake of arginine-rich cell-penetrating peptides
- 2011
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 2, s. 453-
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Tidskriftsartikel (refereegranskat)abstract
- In addition to endocytosis-mediated cellular uptake, hydrophilic cell-penetrating peptides are able to traverse biological membranes in a non-endocytic mode termed transduction, resulting in immediate bioavailability. Here we analysed structural requirements for the non-endocytic uptake mode of arginine-rich cell-penetrating peptides, by a combination of live-cell microscopy, molecular dynamics simulations and analytical ultracentrifugation. We demonstrate that the transduction efficiency of arginine-rich peptides increases with higher peptide structural rigidity. Consequently, cyclic arginine-rich cell-penetrating peptides showed enhanced cellular uptake kinetics relative to their linear and more flexible counterpart. We propose that guanidinium groups are forced into maximally distant positions by cyclization. This orientation increases membrane contacts leading to enhanced cell penetration.
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| 2. |
- Palm-Apergi, Caroline, et al.
(författare)
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A new rapid cell-penetrating peptide based strategy to produce bacterial ghosts for plasmid delivery
- 2008
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Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 132:1, s. 49-54
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Tidskriftsartikel (refereegranskat)abstract
- The production of bacterial ghosts involves the lysis gene E plasmid in order to lyse and empty the bacteria of their cytoplasmic contents. After lysis the ghosts can either be loaded with new desired DNA and used for delivery to mammalian cells or used in vaccination. Cell-penetrating peptides have been used as delivery vehicles of drugs and oligonucleotides. Although many of them show low toxicity they have been compared to antimicrobial peptides involved in innate immunity. Recently we showed that cell-penetrating peptides also could be antimicrobial. In this study we take advantage of the antimicrobial effect of one cell-penetrating peptide, namely MAP, which is a model amphipathic peptide and treat bacteria with the peptide to produce bacterial ghosts. This new peptide based strategy is not dependent on the lysis gene E plasmid thus; several tiresome steps are removed in the production of ghosts. In addition the ghosts can be preloaded with a desired plasmid or DNA further removing time consuming reprocessing steps. To our knowledge this is the first study that uses a cell-penetrating peptide based strategy to produce bacterial ghosts to be used in plasmid delivery.
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| 3. |
- Palm Apergi, Caroline, 1978-
(författare)
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Design and evaluation of drug delivery vehicles
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A crucial aspect of drug delivery is efficient transport to the site of action. Thus, there is a need to design and evaluate new delivery vehicles. In this thesis two delivery vehicles, cell-penetrating peptides and bacterial ghosts, were evaluated. The understanding of the internalization and degradation kinetics of cell-penetrating peptides is important for the practical aspects of cargo delivery since peptides have a notorious reputation of being rapidly degraded. If the cell-penetrating peptide remains intact inside the cellular environment, there is a possibility that the peptide-cargo conjugate leaks back to the extracellular environment. However, if it is degraded outside the cell, the cargo will never be delivered. In order to improve uptake efficiency and to be able to foresee side effects, the translocation mechanism needs to be fully elucidated. Data gathered from the first two papers led to the proposal of a new me-chanism involved in cell-penetrating peptide uptake: the membrane repair response, a resealing mechanism rapidly patching up broken membranes. This mechanism could explain the divergence in perception concerning the uptake pathways. Furthermore a new assay to produce the second delivery vehicle, bacterial ghosts, was developed based on data from the cell-penetrating peptide investigations. Bacterial ghosts are dead bacteria devoid of cytoplasmic contents but still retaining their structural and morphological characteristics, after protein E lysis of the bacterial cell membrane. By using a cell-penetrating peptide with antimicrobial effects, a new rapid peptide-based strategy to produce ghosts was developed and the capability to deliver plasmid DNA into the cell for expression was evaluated.
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| 4. |
- Palm-Apergi, Caroline, et al.
(författare)
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The membrane repair response masks membrane disturbances caused by cell-penetrating peptide uptake
- 2009
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 23:1, s. 214-223
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Tidskriftsartikel (refereegranskat)abstract
- Although cell-penetrating peptides are able to deliver cargo into cells, their uptake mechanism is still not fully understood and needs to be elucidated to improve their delivery efficiency. Herein, we present evidence of a new mechanism involved in uptake, the membrane repair response. Recent studies have suggested that there might be a direct penetration of peptides in parallel with different forms of endocytosis. The direct penetration of hydrophilic peptides through the hydrophobic plasma membrane, however, is highly controversial. Three proteins involved in target cell apoptosis—perforin, granulysin, and granzymes—share many features common in uptake of cell-penetrating peptides (e.g., they bind proteoglycans). During perforin uptake, the protein activates the membrane repair response, a resealing mechanism triggered in cells with injured plasma membrane, because of extracellular calcium influx. On activation of the membrane repair response, internal vesicles are mobilized to the site of the disrupted plasma membrane, resealing it within seconds. In this study, we have used flow cytometry, fluorescence, and electron microscopy, together with high-performance liquid chromatography and mass spectrometry, to present evidence that the membrane repair response is able to mask damages caused during cell-penetrating peptide uptake, thus preventing leakage of endogenous molecules out of the cell.—Palm-Apergi, C., Lorents, A., Padari, K., Pooga, M., and Hällbrink, M. The membrane repair response masks membrane disturbances caused by cell-penetrating peptide uptake.
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| 5. |
- Shah, Kinjal, et al.
(författare)
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PLK1 as a cooperating partner for BCL2-mediated antiapoptotic program in leukemia
- 2023
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Ingår i: Blood Cancer Journal. - 2044-5385. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The deregulation of BCL2 family proteins plays a crucial role in leukemia development. Therefore, pharmacological inhibition of this family of proteins is becoming a prevalent treatment method. However, due to the emergence of primary and acquired resistance, efficacy is compromised in clinical or preclinical settings. We developed a drug sensitivity prediction model utilizing a deep tabular learning algorithm for the assessment of venetoclax sensitivity in T-cell acute lymphoblastic leukemia (T-ALL) patient samples. Through analysis of predicted venetoclax-sensitive and resistant samples, PLK1 was identified as a cooperating partner for the BCL2-mediated antiapoptotic program. This finding was substantiated by additional data obtained through phosphoproteomics and high-throughput kinase screening. Concurrent treatment using venetoclax with PLK1-specific inhibitors and PLK1 knockdown demonstrated a greater therapeutic effect on T-ALL cell lines, patient-derived xenografts, and engrafted mice compared with using each treatment separately. Mechanistically, the attenuation of PLK1 enhanced BCL2 inhibitor sensitivity through upregulation of BCL2L13 and PMAIP1 expression. Collectively, these findings underscore the dependency of T-ALL on PLK1 and postulate a plausible regulatory mechanism. [Figure not available: see fulltext.]
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