LL-37-induced caspase-independent apoptosis is associated with plasma membrane permeabilization in human osteoblast-like cells
(2021) In Peptides 135.- Abstract
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... (More)
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.
(Less)
- author
- Bankell, Elisabeth LU ; Dahl, Sara LU ; Gidlöf, Olof LU ; Svensson, Daniel LU and Nilsson, Bengt Olof LU
- organization
- publishing date
- 2021-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Antimicrobial peptides (AMP), Apoptosis, Cathelicidin, Cytotoxicity, Innate immunity
- in
- Peptides
- volume
- 135
- article number
- 170432
- publisher
- Elsevier
- external identifiers
-
- pmid:33129893
- scopus:85095782621
- ISSN
- 0196-9781
- DOI
- 10.1016/j.peptides.2020.170432
- language
- English
- LU publication?
- yes
- id
- 25394ad3-0846-4401-8783-0168e123f308
- date added to LUP
- 2020-12-08 13:07:14
- date last changed
- 2024-09-19 10:31:16
@article{25394ad3-0846-4401-8783-0168e123f308, abstract = {{<p>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.</p>}}, author = {{Bankell, Elisabeth and Dahl, Sara and Gidlöf, Olof and Svensson, Daniel and Nilsson, Bengt Olof}}, issn = {{0196-9781}}, keywords = {{Antimicrobial peptides (AMP); Apoptosis; Cathelicidin; Cytotoxicity; Innate immunity}}, language = {{eng}}, publisher = {{Elsevier}}, series = {{Peptides}}, title = {{LL-37-induced caspase-independent apoptosis is associated with plasma membrane permeabilization in human osteoblast-like cells}}, url = {{http://dx.doi.org/10.1016/j.peptides.2020.170432}}, doi = {{10.1016/j.peptides.2020.170432}}, volume = {{135}}, year = {{2021}}, }