| Title: |
Exoenzyme Y Induces Extracellular Active Caspase-7 Accumulation Independent From Apoptosis: Modulation of Transmissible Cytotoxicity |
| Authors: |
Renema, Phoibe; Kozhukhar, Natalya; Pastukh, Viktoriya; Spadafora, Domenico; Paudel, Sunita Subedi; Tambe, Dhananjay T.; Alexeyev, Mikhail; Frank, Dara W.; Stevens, Troy |
| Source: |
University Faculty and Staff Publications |
| Publisher Information: |
JagWorks@USA |
| Publication Year: |
2020 |
| Subject Terms: |
Amyloid; Caspase-3; Pseudomonas aeruginosa; Tau; Transmissible cytotoxicity; Medicine and Health Sciences |
| Description: |
Caspase-3 and -7 are executioner caspases whose enzymatic activity is necessary to complete apoptotic cell death. Here, we questioned whether endothelial cell infection leads to caspase-3/7-mediated cell death. Pulmonary microvascular endothelial cells (PMVECs) were infected with Pseudomonas aeruginosa (PA103). PA103 caused cell swelling with a granular appearance, paralleled by intracellular caspase-3/7 activation and cell death. In contrast, PMVEC infection with ExoY+ (PA103 ΔexoUexoT::Tc pUCPexoY) caused cell rounding, but it did not activate intracellular caspase-3/7 and it did not cause cell death. However, ExoY+ led to a time-dependent accumulation of active caspase-7, but not caspase-3, in the supernatant, independent of apoptosis. To study the function of extracellular caspase-7, caspase-7- and caspase-3-deficient PMVECs were generated using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology. Caspase-7 activity was significantly reduced in supernatants from infected caspase-7-deficient cells but was unchanged in supernatants from infected caspase-3 deficient cells, indicating an uncoupling in the mechanism of activation of these two enzymes. Because ExoY+ leads to the release of heat stable amyloid cytotoxins that are responsible for transmissible cytotoxicity, we next questioned whether caspase-7 contributes to the severity of this process. Supernatants obtained from infected caspase-7-deficient cells displayed significantly reduced transmissible cytotoxicity when compared with supernatants from infected wild-type controls, illustrating an essential role for caspase-7 in promoting the potency of transmissible cytotoxicity. Thus, we report a mechanism whereby ExoY+ infection induces active caspase-7 accumulation in the extracellular space, independent of both caspase-3 and cell death, where it modulates ExoY+-induced transmissible cytotoxicity. |
| Document Type: |
text |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
https://jagworks.southalabama.edu/usa_faculty_staff_pubs/179; https://jagworks.southalabama.edu/context/usa_faculty_staff_pubs/article/1210/viewcontent/ajplung.00508.2019.pdf |
| DOI: |
10.1152/ajplung.00508.2019 |
| Availability: |
https://jagworks.southalabama.edu/usa_faculty_staff_pubs/179; https://doi.org/10.1152/ajplung.00508.2019; https://jagworks.southalabama.edu/context/usa_faculty_staff_pubs/article/1210/viewcontent/ajplung.00508.2019.pdf |
| Accession Number: |
edsbas.278427E |
| Database: |
BASE |