Targeting USP11 may alleviate radiation-induced pulmonary fibrosis by regulating endothelium tight junction

USP11 Exacerbates Radiation-Induced Pneumonitis by Activating Endothelial Cell Inflammatory Response via OTUD5-STING Signaling

PURPOSE

Radiation-induced pneumonitis (RIP) seriously limits the application of radiation therapy in the treatment of thoracic tumors, and its etiology and pathogenesis remain elusive. This study aimed to elucidate the role of ubiquitin-specific peptidase 11 (USP11) in the progression of RIP and the associated underlying mechanisms.

METHODS AND MATERIALS

Changes in cytokines and infiltrated immune cells were detected by enzyme-linked immunosorbent assays and immunohistochemistry after exposure to 20 Gy x-ray with whole-thorax irradiation. The effects of USP11 expression on endothelial cell proliferation and apoptosis were analyzed by costaining of CD31/Ki67 and CD31/caspase-3 in vivo, and the production of cytokines and reactive oxygen species was confirmed by reverse-transcription polymerase chain reaction and flow cytometry in vitro. Comprehensive proteome and ubiquitinome analyses were used for USP11 substrate screening after radiation. Results were verified by Western blotting and coimmunoprecipitation experiments. Recombinant adeno-associated virus lung vectors expressing OTUD5 were used for localized overexpression of OTUD5 in mouse pulmonary tissue, and immunohistochemistry was conducted to analyze cytokine expression.

RESULTS

The progression of RIP was significantly alleviated by reduced expression of proinflammatory cytokines in both Usp11-knockout (Usp11-/-) mice and in mice treated with the USP11 inhibitor mitoxantrone. Likewise, the absence of USP11 resulted in decreased permeability of pulmonary vessels and neutrophils and macrophage infiltration. The proliferation rates of endothelial cells were prominently increased in the Usp11-/- lung, whereas apoptosis in Usp11-/- lungs decreased after irradiation compared with that observed in Usp11+/+ lungs. Conversely, USP11 overexpression increased proinflammatory cytokine expression and reactive oxygen species production in endothelial cells after radiation. Comprehensive proteome and ubiquitinome analyses indicated that USP11 overexpression upregulates the expression of several deubiquitinating enzymes, including USP22, USP33, and OTUD5. We demonstrate that USP11 deubiquitinates OTUD5 and implicates the OTUD5-STING signaling pathway in the progression of the inflammatory response in endothelial cells.

CONCLUSIONS

USP11 exacerbates RIP by triggering an inflammatory response in endothelial cells both in vitro and in vivo, and the OTUD5-STING pathway is involved in the USP11-dependent promotion of RIP. This study provides experimental support for the development of precision intervention strategies targeting USP11 to mitigate RIP.

USP11 plays a critical role in the onset and progression of acute graft-versus-host disease：Novel target for precision therapeutics

Acute graft-versus-host disease (aGvHD) is considered a result of "cytokine storm." Targeted therapeutic interventions on cytokines via ubiquitination regulatory pathways may provide a potential approach for aGvHD treatment. Ubiquitin-specific peptidase 11 (USP11) has been reported to play key roles in a variety of physiopathological processes by regulating the stability and function of several vital protein molecules. However, its role in aGvHD remains unclear. In this study, we identified USP11 was associated with aGvHD in patients. In the aGvHD mouse model, the colon and liver were more seriously affected in recipient mice who received USP11 wt bone marrow (BM) cells and eased after the donor was treated with a USP11 inhibitor or received USP11 ko BM cells. In mouse models, IL-6 was identified as a major effecter in accelerating aGvHD induced by USP11. In the cell model, IL-6 mRNA transcript was affected by USP11. In addition, USP11 also inhibited IL-6 degradation by affecting IL-6 ubiquitination. Furthermore, the positive correlation between USP11 and IL-6 was confirmed in the GvHD patients' samples. Collectively, all results indicated that USP11 played a critical role in the onset and progression of aGvHD. USP11 might be a potential target for aGvHD treatment.

Clinical Trial in a Dish for Space Radiation Countermeasure Discovery

NASA aims to return humans to the moon within the next five years and to land humans on Mars in a few decades. Space radiation exposure represents a major challenge to astronauts' health during long-duration missions, as it is linked to increased risks of cancer, cardiovascular dysfunctions, central nervous system (CNS) impairment, and other negative outcomes. Characterization of radiation health effects and developing corresponding countermeasures are high priorities for the preparation of long duration space travel. Due to limitations of animal and cell models, the development of novel physiologically relevant radiation models is needed to better predict these individual risks and bridge gaps between preclinical testing and clinical trials in drug development. "Clinical Trial in a Dish" (CTiD) is now possible with the use of human induced pluripotent stem cells (hiPSCs), offering a powerful tool for drug safety or efficacy testing using patient-specific cell models. Here we review the development and applications of CTiD for space radiation biology and countermeasure studies, focusing on progress made in the past decade.

Identification of key pathways and genes in the progression of silicosis based on WGCNA

Silicosis, induced by inhaling silica particles in workplaces, is one of the most common occupational diseases. The prognosis of silicosis and its consequent fibrosis is extremely poor due to limited treatment modalities and lack of understanding of the disease mechanisms. In this study, a Wistar rat model for silicosis fibrosis was established by intratracheal instillation of silica (0, 50, 100 and 200 mg/mL, 1 mL) with the evidence of Hematoxylin and Eosin (HE) and Masson staining and the expressions of inflammatory and fibrotic proteins of rats' lung tissues. RNA of lung tissues of rats exposed to 200 mg/mL silica particles and normal saline for 14 d and 28 d was extracted and sequenced to detect differentially expressed genes (DEGs) and to identify silicosis fibrosis-associated modules and hub genes by Weighted gene co-expression network analysis (WGCNA). Predictions of gene functions and signaling pathways were conducted using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. In this study, it has been demonstrated the promising role of the Hippo signaling pathway in silicosis fibrosis, which will be conducive to elucidating the specific mechanism of pulmonary fibrosis induced by silica and to determining molecular initiating event (MIE) and adverse outcome pathway (AOP) of silicosis fibrosis.