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

Abstract

Purpose

Radiation-induced pulmonary fibrosis (RIPF) is a major side effect after radiotherapy for thoracic malignancies. However, rare anti-RIPF therapeutics show definitive effects for treating this disease. Ubiquitin-specific peptidase 11 (USP11) has been reported to promote transforming growth factor β (TGFβ) signaling which plays an essential role underlying RIPF. Herein, we explored the role of USP11 on RIPF.

Materials and methods

In the present study, USP11-knockout (Usp11^-/-) mice were used to explore the effects of USP11 on RIPF. The lung tissue was obtained after receiving 30 Gy X-ray irradiation. The expression of USP11, TGF-β1, and a-SMA was determined by immunohistochemical and Western Blot, respectively. γ-H₂AX foci and TUNEL positive cells were detected by fluorescent technique to assess DNA damage and apoptosis. High-throughput proteomic analysis was applied to further explore the related mechanisms. The transwell co-culture method was used to investigate bystander effects in HELF cells induced by irradiated HMEC-1 cells in vitro.

Results

Here we found that radiation activated USP11 in vivo and in vitro. Our results showed that USP11 deficiency effectively decreased serum TGF-β1 level, suppressed α-SMA expression, and mitigated pulmonary fibrosis. In addition, fewer γ-H₂AX foci and decreased apoptotic cells were identified after irradiation in the primary cells isolated from the lungs of Usp11^-/- mice. High-throughput proteomics analysis results showed that 22-upregulated and 158-downregulated proteins were identified in the lung tissues of Usp11^-/- mice after irradiation. Furthermore, gene set enrichment analysis (GSEA) revealed that USP11 deficiency affects the tight junction signaling pathway.

Conclusions

We verified that USP11 deficiency remarkably reinforced tight junction in the endothelial cells and alleviated TGF-β1 to inhibit fibrosis of fibroblast cells. The present study preliminarily showed that USP11-knockout mitigated RIPF via reinforcement endothelial barrier function.

Keywords:

• USP11
• RIPF
• proteomics
• tight junction
• TGF-β1

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China (nos. U1967220, 82073339, 81773224 and 81773226), Scientific Projects of Jiangsu Province (nos. BE2018643 and BK20191157), China Postdoctoral Science Foundation (nos. 2017M611908 and 2017M610351), Jiangsu Province Postdoctoral Science Foundation (nos. 1701177B), and Scientific Research Program of Changzhou (CE20195048).

Notes on contributors

Yiting Tang

Yingting Tang, PhD candidate, her research interest is the biological effects of ionizing radiation.

Qian Yuan

Qian Yuan, MD, her research field is Radiation Medicine.

Congzhao Zhao

Congzhao Zhao, MD, his research field is Radiation Medicine.

Ying Xu

Ying Xu, MD, her research interest is the biological effects of ionizing radiation.

Qi Zhang

Yang Jiao, Jianping Cao, Qi Zhang, PhD, are Professors of State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University.

Lili Wang

Lili Wang, PhD, MD, her research field is Radiation Oncology, is a Professor of the Department of Radiotherapy, The First Affiliated Hospital of Soochow University.

Zhiqiang Sun

Judong Luo, Zhiqiang Sun, PhD, MD, are Professors of Department of Radiotherapy, The Affiliated Changzhou No. 2 People’s Hospital of Nanjing Medical University.

Jianping Cao

Yang Jiao, Jianping Cao, Qi Zhang, PhD, are Professors of State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University.

Judong Luo

Judong Luo, Zhiqiang Sun, PhD, MD, are Professors of Department of Radiotherapy, The Affiliated Changzhou No. 2 People’s Hospital of Nanjing Medical University.

Yang Jiao

Yang Jiao, Jianping Cao, Qi Zhang, PhD, are Professors of State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University.