BACKGROUND: Radiation-induced intestinal injury (RIII) interrupts the scheduled processes of abdominal and pelvic radiotherapy (RT) and compromises the quality of life of cancer survivors. However, the specific regulators and mechanisms underlying the effects of RIII remain unknown. The biological effects of RT are caused primarily by DNA damage, and ataxia telangiectasia mutated (ATM) is a core protein of the DNA damage response (DDR). However, whether ATM is regulated by deubiquitination signaling remains unclear. METHODS: We established animal and cellular models of RIII. The effects of ubiquitin-specific protease 15 (USP15) on DNA damage and radion-induced intestinal injury were evaluated. Mass spectrometry analysis, truncation tests, and immunoprecipitation were used to identify USP15 as a binding partner of ATM and to investigate the ubiquitination of ATM. Finally, the relationship between the USP15/ATM axes was further determined via subsequent experiments. RESULTS: In this study, we identified the deubiquitylating enzyme USP15 as a regulator of DNA damage and the pathological progression of RIII. Irradiation upregulates the expression of USP15, whereas pharmacological inhibition of USP15 exacerbates radiation-induced DNA damage and RIII both in vivo and in vitro. Mechanistically, USP15 interacts with, deubiquitinates, and stabilises ATM via K48-linked deubiquitination. Notably, ATM overexpression blocks the effect of USP15 genetic inhibition on DNA damage and RIII progression. CONCLUSIONS: These findings describe ATM as a novel deubiquitination target of USP15 upon radiation-induced DNA damage and intestinal injury, and provides experimental support for USP15/ATM axis as a potential target for developing strategies that mitigate RIII.

• MeSH
• ATM protein * metabolismus   genetika   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• poškození DNA * MeSH
• radiační poranění metabolismus   genetika   MeSH
• specifické proteázy ubikvitinu * metabolismus   genetika   MeSH
• střeva účinky záření   patologie   MeSH
• ubikvitinace * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND AND PURPOSE: Radiation-induced intestinal injury (RIII) compromises the clinical utility of pelvic radiotherapy (RT). We aimed to explore the protective effect and underlying mechanism of (-)-epigallocatechin-3-gallate (EGCG) on RIII. MATERIALS AND METHODS: We evaluated the protective effect of EGCG on intestine in RIII mouse model and pelvic cancer patients, while explored the underlying mechanism through (1) 16S rRNA sequencing, (2) metabolomic profiles, (3) fresh sterile fecal filtrate (SFF) transplantation, and (4) transcriptome sequencing. RESULTS: EGCG efficiently prevented RIII in mouse, as reflected by improved survival, alleviated intestinal structure damage, promoted intestinal regeneration, and ameliorated gut microbiota dysbiosis. Prophylactic EGCG intervention reduced the severity of RIII in patients receiving pelvic RT. Mechanistically, the protective effect of EGCG could be transferred to other mice by SFF transplantation. EGCG enriched gut microbiota-derived metabolite D-tagatose, and oral administration of D-tagatose reproduced the radio-protective effect of EGCG via activating AMPK. CONCLUSION: Oral EGCG may be a promising strategy for preventing RIII clinically, and warrant further investigation in prospective randomized phase III trials.

• MeSH
• katechin * analogy a deriváty   farmakologie   MeSH
• lidé MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádory pánve * radioterapie   MeSH
• proteinkinasy aktivované AMP metabolismus   MeSH
• radiační poranění * prevence a kontrola   MeSH
• radioprotektivní látky farmakologie   terapeutické užití   MeSH
• střeva účinky záření   účinky léků   mikrobiologie   MeSH
• střevní mikroflóra * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH