UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1
GADD45a is a gene we previously reported as a mediator of responses to acute lung injury. GADD45a−/− mice express decreased Akt and increased Akt ubiquitination due to the reduced expression of UCHL1 (ubiquitin c-terminal hydrolase L1), a deubiquitinating enzyme, while GADD45a−/− mice have increased...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-10-01
|
| Series: | Cells |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4409/12/19/2405 |
| _version_ | 1797576051680870400 |
|---|---|
| author | Yulia Epshtein Biji Mathew Weiguo Chen Jeffrey R. Jacobson |
| author_facet | Yulia Epshtein Biji Mathew Weiguo Chen Jeffrey R. Jacobson |
| author_sort | Yulia Epshtein |
| collection | DOAJ |
| description | GADD45a is a gene we previously reported as a mediator of responses to acute lung injury. GADD45a−/− mice express decreased Akt and increased Akt ubiquitination due to the reduced expression of UCHL1 (ubiquitin c-terminal hydrolase L1), a deubiquitinating enzyme, while GADD45a−/− mice have increased their susceptibility to radiation-induced lung injury (RILI). Separately, we have reported a role for sphingolipids in RILI, evidenced by the increased RILI susceptibility of SphK1−/− (sphingosine kinase 1) mice. A mechanistic link between UCHL1 and sphingolipid signaling in RILI is suggested by the known polyubiquitination of SphK1. Thus, we hypothesized that the regulation of SphK1 ubiquitination by UCHL1 mediates RILI. Initially, human lung endothelial cells (EC) subjected to radiation demonstrated a significant upregulation of UCHL1 and SphK1. The ubiquitination of EC SphK1 after radiation was confirmed via the immunoprecipitation of SphK1 and Western blotting for ubiquitin. Further, EC transfected with siRNA specifically for UCHL1 or pretreated with LDN-5744, as a UCHL1 inhibitor, prior to radiation were noted to have decreased ubiquitinated SphK1 in both conditions. Further, the inhibition of UCHL1 attenuated sphingolipid-mediated EC barrier enhancement was measured by transendothelial electrical resistance. Finally, LDN pretreatment significantly augmented murine RILI severity. Our data support the fact that the regulation of SphK1 expression after radiation is mediated by UCHL1. The modulation of UCHL1 affecting sphingolipid signaling may represent a novel RILI therapeutic strategy. |
| first_indexed | 2024-03-10T21:47:59Z |
| format | Article |
| id | doaj.art-cc7629dd72504c6eb730d3d408293d4b |
| institution | Directory Open Access Journal |
| issn | 2073-4409 |
| language | English |
| last_indexed | 2024-03-10T21:47:59Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cells |
| spelling | doaj.art-cc7629dd72504c6eb730d3d408293d4b2023-11-19T14:13:21ZengMDPI AGCells2073-44092023-10-011219240510.3390/cells12192405UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1Yulia Epshtein0Biji Mathew1Weiguo Chen2Jeffrey R. Jacobson3Department of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Illinois at Chicago, Chicago, IL 60612, USADepartment of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Illinois at Chicago, Chicago, IL 60612, USADepartment of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Illinois at Chicago, Chicago, IL 60612, USADepartment of Medicine, Division of Pulmonary, Critical Care, Sleep and Allergy, University of Illinois at Chicago, Chicago, IL 60612, USAGADD45a is a gene we previously reported as a mediator of responses to acute lung injury. GADD45a−/− mice express decreased Akt and increased Akt ubiquitination due to the reduced expression of UCHL1 (ubiquitin c-terminal hydrolase L1), a deubiquitinating enzyme, while GADD45a−/− mice have increased their susceptibility to radiation-induced lung injury (RILI). Separately, we have reported a role for sphingolipids in RILI, evidenced by the increased RILI susceptibility of SphK1−/− (sphingosine kinase 1) mice. A mechanistic link between UCHL1 and sphingolipid signaling in RILI is suggested by the known polyubiquitination of SphK1. Thus, we hypothesized that the regulation of SphK1 ubiquitination by UCHL1 mediates RILI. Initially, human lung endothelial cells (EC) subjected to radiation demonstrated a significant upregulation of UCHL1 and SphK1. The ubiquitination of EC SphK1 after radiation was confirmed via the immunoprecipitation of SphK1 and Western blotting for ubiquitin. Further, EC transfected with siRNA specifically for UCHL1 or pretreated with LDN-5744, as a UCHL1 inhibitor, prior to radiation were noted to have decreased ubiquitinated SphK1 in both conditions. Further, the inhibition of UCHL1 attenuated sphingolipid-mediated EC barrier enhancement was measured by transendothelial electrical resistance. Finally, LDN pretreatment significantly augmented murine RILI severity. Our data support the fact that the regulation of SphK1 expression after radiation is mediated by UCHL1. The modulation of UCHL1 affecting sphingolipid signaling may represent a novel RILI therapeutic strategy.https://www.mdpi.com/2073-4409/12/19/2405UCHL1sphingosine kinase 1radiation lung injury |
| spellingShingle | Yulia Epshtein Biji Mathew Weiguo Chen Jeffrey R. Jacobson UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 Cells UCHL1 sphingosine kinase 1 radiation lung injury |
| title | UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 |
| title_full | UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 |
| title_fullStr | UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 |
| title_full_unstemmed | UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 |
| title_short | UCHL1 Regulates Radiation Lung Injury via Sphingosine Kinase-1 |
| title_sort | uchl1 regulates radiation lung injury via sphingosine kinase 1 |
| topic | UCHL1 sphingosine kinase 1 radiation lung injury |
| url | https://www.mdpi.com/2073-4409/12/19/2405 |
| work_keys_str_mv | AT yuliaepshtein uchl1regulatesradiationlunginjuryviasphingosinekinase1 AT bijimathew uchl1regulatesradiationlunginjuryviasphingosinekinase1 AT weiguochen uchl1regulatesradiationlunginjuryviasphingosinekinase1 AT jeffreyrjacobson uchl1regulatesradiationlunginjuryviasphingosinekinase1 |