LL-37-induced caspase-independent apoptosis is associated with plasma membrane permeabilization in human osteoblast-like cells
| Autor: | Olof Gidlöf, Daniel Svensson, Bengt-Olof Nilsson, Sara Dahl, Elisabeth Bankell |
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| Rok vydání: | 2021 |
| Předmět: |
Cell Membrane Permeability
Physiology Poly ADP ribose polymerase Apoptosis 030209 endocrinology & metabolism Biochemistry Flow cytometry 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine Endocrinology Cathelicidins Annexin medicine Humans Viability assay Cytotoxicity Osteoblasts TUNEL assay medicine.diagnostic_test Caspase-Independent Apoptosis Chemistry Cell Membrane Molecular biology Caspases 030217 neurology & neurosurgery Antimicrobial Cationic Peptides |
| Zdroj: | Peptides. 135:170432 |
| ISSN: | 0196-9781 |
| Popis: | The host defense peptide LL-37 is active against both gram-positive and gram-negative bacteria, but it has also been shown to reduce human host cell viability. However, the mechanisms behind LL-37-induced human host cell cytotoxicity are not yet fully understood. Here, we assess if LL-37-evoked attenuation of human osteoblast-like MG63 cell viability is associated with apoptosis, and if the underlying mechanism may involve LL-37-induced plasma membrane permeabilization. MG63 cell viability and plasma membrane permeabilization were investigated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and by measuring lactate dehydrogenase (LDH) release, respectively. Apoptosis was assessed by the terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) assay and Annexin V flow cytometry, and caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavage were determined by Western blot. LL-37 (4 and 10 μM) reduced both cell number and cell viability, and these effects were associated with a pro-apoptotic effect demonstrated by positive TUNEL staining and Annexin V flow cytometry. LL-37-induced apoptosis was not coupled to either caspase-3 or PARP cleavage, suggesting that LL-37 causes caspase-independent apoptosis in MG63 cells. Both LL-37 and the well-known plasma membrane permeabilizer Triton X-100 reduced cell viability and stimulated LDH release. Triton X-100-treated cells showed positive TUNEL staining, and the detergent accumulated cells in late apoptosis/necrosis. Similar to LL-37, Triton X-100 caused no PARP cleavage. We conclude that LL-37 promotes caspase-independent apoptosis, and that this effect seems coupled to plasma membrane permeabilization in human MG63 cells. |
| Databáze: | OpenAIRE |
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