PPM1G regulates hepatic ischemia/reperfusion injury through STING-mediated inflammatory pathways in macrophages.
Immun Inflamm Dis
; 12(2): e1189, 2024 Feb.
Article
in En
| MEDLINE
| ID: mdl-38372470
ABSTRACT
BACKGROUND:
Ischemia/reperfusion injury (IRI) is generally unavoidable following liver transplantation. Here, we investigated the role of protein phosphatase, Mg2+ /Mn2+ dependent 1G (PPM1G) in hepatic IRI.METHODS:
Hepatic IRI was mimicked by employing a hypoxia/reperfusion (H/R) model in RAW 264.7 cells and a 70% warm ischemia model in C57BL/6 mice, respectively. In vitro, expression changes of tumor necrosis factor-α and interleukin were detected by quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis, and enzyme-linked immunosorbent assay. The protein expressions of PPM1G and the stimulator of interferon genes (STING) pathway components were analyzed by western blot. Interaction between PPM1G and STING was verified by coimmunoprecipitation (CO-IP). Immunofluorescence was applied for detection of p-IRF3. Flow cytometry, qRT-PCR and western blot were utilized to analyze markers of macrophage polarization. In vivo, histological analyses of mice liver were carried out by TUNEL and H&E staining. Changes in serum aminotransferases were also detected.RESULTS:
Following H/R intervention, a steady decline in PPM1G along with an increase in inflammatory cytokines in vitro was observed. Addition of plasmid with PPM1G sequence limited the release of inflammatory cytokines and downregulated phosphorylation of STING. CO-IP validated the interaction between PPM1G and STING. Furthermore, inhibition of PPM1G with lentivirus enhanced phosphorylation of STING and its downstream components; meanwhile, p65, p38, and Jnk were also surged to phosphorylation. Expression of INOS and CD86 was surged, while CD206, Arg-1, and IL-10 were inhibited. In vivo, PPM1G inhibition further promoted liver damage, hepatocyte apoptosis, and transaminases release. Selective inhibition of STING with C-176 partially reversed the activation of STING pathway and inflammatory cytokines in vitro. M1 markers were also suppressed by C-176. In vivo, C-176 rescued liver damage and transaminase release caused by PPM1G inhibition.CONCLUSION:
PPM1G suppresses hepatic IRI and macrophage M1 phenotype by repressing STING-mediated inflammatory pathways.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Reperfusion Injury
/
Protein Phosphatase 2C
/
Liver Diseases
Limits:
Animals
Language:
En
Journal:
Immun Inflamm Dis
/
Immun. Inflamm. Dis
/
Immunity, inflammation and disease
Year:
2024
Document type:
Article
Affiliation country:
Country of publication: