Von Willebrand factor promotes radiation-induced intestinal injury (RIII) development and its cleavage enzyme rhADAMTS13 protects against RIII by reducing inflammation and oxidative stress.

Patients with abdominopelvic cancer undergoing radiotherapy commonly develop radiation-induced intestinal injury (RIII); however, its underlying pathogenesis remains elusive. The von Willebrand factor (vWF)/a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) axis has been implicated in thrombosis, inflammation, and oxidative stress. However, its role in RIII remains unclear. In this study, the effect of radiation on vWF and ADAMTS13 expression was firstly evaluated in patients with cervical cancer undergoing radiotherapy and C57BL/6J mice exposed to different doses of total abdominal irradiation. Then, mice with the specific deletion of vWF in the platelets and endothelium were established to demonstrate the contribution of vWF to RIII. Additionally, the radioprotective effect of recombinant human (rh) ADAMTS13 against RIII was assessed. Results showed that both the patients with cervical cancer undergoing radiotherapy and RIII mouse model exhibited increased vWF levels and decreased ADAMTS13 levels. The knockout of platelet- and endothelium-derived vWF rectified the vWF/ADAMTS13 axis imbalance; improved intestinal structural damage; increased crypt epithelial cell proliferation; and reduced radiation-induced apoptosis, inflammation, and oxidative stress, thereby alleviating RIII. Administration of rhADAMTS13 could equally alleviate RIII. Our results demonstrated that abdominal irradiation affected the balance of the vWF/ADAMTS13 axis. vWF exerted a deleterious role and ADAMTS13 exhibited a protective role in RIII progression. rhADAMTS13 has the potential to be developed into a radioprotective agent.

Recombinant human ADAMTS13 ameliorates radiation-induced intestinal injury by regulating inflammation and oxidative stress / 中华放射医学与防护杂志

Objective:To study the protective effect of recombinant human ADAMTS13 (rhADAMTS13) on radiation-induced intestinal injury.Methods:Thirty C57BL/6 J mice were randomly divided into healthy control group, 12 Gy abdominal irradiation group (simple irradiation group) and rhADAMTS13 combined with 12 Gy irradiation group (combined group) with 6, 12 and 12 mice per group. The combined group was given 2.5 μg/kg rhADAMTS13 via tail vein injection 3 d before irradiation. 12 Gy X-ray abdominal irradiation was given to the simple irradiation group.The mice were executed at 1 and 3 d after irradiation, and plasma vWF, ADAMTS13 and CRP concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Intestinal histopathological changes were observed by hematoxylin-eosin (HE) staining.Intestinal Ki67, TNF- α and MPO expression levels were detected by immunohistochemical staining.Plasma malondialdehyde (MDA), superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) were measured by biochemical kits.Results:Compared with the healthy control group, the plasma vWF level was increased( t=6.20、12.29, P<0.05) and ADAMTS13 level was decreased( t=9.82、22.83, P<0.05)in mice at 1(1.38±0.11)and 3 (1.70±0.10)after irradiation.Compared with the simple irradiation group, the plasma vWF level was reduced ( t=2.93, 3.96, P<0.05) and ADAMTS13 level was increased ( t=5.09, 9.82, P<0.05) in mice at 1 (1.23±0.12) and 3 d (1.48±0.09) after irradiation in the combined group. Immunohistochemical staining showed that the number of Ki67 + cells in the crypt of the combined group increased significantly ( t=9.82, P<0.05) and the degree of TNF-α and MPO infiltration decreased significantly ( t=15.44, 14.33, P<0.05) compared with the simple irradiation group.In addition, rhADAMTS13 intervention significantly reduced plasma CRP ( t=5.02, 2.96, P<0.05) and MDA ( t=2.47, 2.55, P<0.05), but increased SOD activity ( t=2.64, 5.64, P<0.05) and T-AOC ( t=3.05, 5.07, P<0.05). Conclusions:rhADAMTS13 attenuates radiation-induced intestinal injury in mice by reducing the levels of inflammation and oxidative stress, providing a new strategy for the protection of radiation-induced intestinal injury.

ADAMTS13 protects mice against renal ischemia-reperfusion injury by reducing inflammation and improving endothelial function.

Acute kidney injury (AKI) is a serious condition without efficient therapeutic options. Recent studies have indicated that recombinant human a disintegrin and metalloprotease with thrombospondin motifs 13 (rhADAMTS13) provides protection against inflammation. Therefore, we hypothesized that ADAMTS13 might protect against AKI by reducing inflammation. Bilateral renal ischemia-reperfusion injury (I/R) was used as AKI models in this study. Prophylactic infusion of rhADAMTS13 was employed to investigate potential mechanisms of renal protection. Renal function, inflammation, and microvascular endothelial function were assessed after 24 h of reperfusion. Our results showed that I/R mice increased plasma von Willebrand factor levels but decreased ADAMTS13 expression. Administration of rhADAMTS13 to I/R mice recovered renal function, histological injury, and apoptosis. Renal inflammation was reduced by rhADAMTS13, accompanied with the downregulation of p38/extracellular signal-regulated protein kinase phosphorylation and cyclooxygenase-2 expression. rhADAMTS13 restored vasodilation in afferent arterioles in I/R mice. Furthermore, rhADAMTS13 treatment enhanced phosphorylation of Akt at Ser473 and eNOS at Ser1177. Administration of the Akt pathway inhibitor wortmannin reduced the protective effect of rhADAMTS13. Our conclusions are that treatment with rhADAMTS13 ameliorates renal I/R injury by reducing inflammation, tubular cell apoptosis, and improving microvascular endothelial dysfunction. rhADAMTS13 could be a promising strategy to treat AKI in clinical settings.