Pharmacological targeting of peptidylarginine deiminase 4 prevents cancer-associated kidney injury in mice

Abstract

Renal insufficiency is a frequent cancer-associated problem affecting more than half of all cancer patients at the time of diagnosis. To minimize nephrotoxic effects the dosage of anticancer drugs are reduced in these patients, leading to sub-optimal treatment efficacy. Despite the severity of this cancer-associated pathology, the molecular mechanisms, as well as therapeutic options, are still largely lacking. We here show that formation of intravascular tumor-induced neutrophil extracellular traps (NETs) is a cause of kidney injury in tumor-bearing mice. Analysis of clinical biomarkers for kidney function revealed impaired creatinine clearance and elevated total protein levels in urine from tumor-bearing mice. Electron microscopy analysis of the kidneys from mice with cancer showed reversible pathological signs such as mesangial hypercellularity, while permanent damage such as fibrosis or necrosis was not observed. Removal of NETs by treatment with DNase I, or pharmacological inhibition of the enzyme peptidylarginine deiminase 4 (PAD4), was sufficient to restore renal function in mice with cancer. Tumor-induced systemic inflammation and impaired perfusion of peripheral vessels could be reverted by the PAD4 inhibitor. In conclusion, the current study identifies NETosis as a previously unknown cause of cancer-associated renal dysfunction and describes a novel promising approach to prevent renal failure in individuals with cancer.

PAD4-dependent NETs generation are indispensable for intestinal clearance of Citrobacter rodentium

“…Studies to date have employed DNase I, which can effectively degrade NETs in vivo , to directly implicate the role of NETs in various experimental disease models 7, 36 . It has been shown that targeting NETs with DNase I could accelerate wound healing 7 and treat disorders such as kidney injury 41 , systemic lupus erythematosus (SLE) 42 , inflammation-associated vascular occlusion 43 and cancer metastasis 44 . Moreover, DNase I (Pulmozyme®) has been utilized clinically as a bona fide first line of treatment for cystic fibrosis without notable side effects 45 .…”

Neutrophil Extracellular Traps in the Establishment and Progression of Renal Diseases

“…Selective PAD4 inhibitors confirm the key role of PAD4 in histone citrullination, NET formation and ANCA production [111,112]. Moreover, administration of PAD4 inhibitors such as 2-chloramidine, YW3-56 and GSK484 before ischemia-reperfusion or in animal models of cancer-associated kidney injury significantly decreases renal damage, necrosis, congestion, and systemic inflammation [34,37,108]. Additionally, the use of the PAD inhibitors Cl-amidine and BB-Cl-amidine in lupus-prone mice modulates NET formation, reduces IFN-regulated gene expression and protects against lupus-dependent damage to the vasculature, kidneys and skin [113].…”

“…The therapeutic potential of novel selective inhibitors of PAD4, the enzyme critical for protein citrullination and NET formation, is currently being explored in preclinical models of cancer-associated kidney injury and autoimmune disease; and it is expected that the efficacy of several such molecules will soon be tested in phase I/II clinical trials [34,37,108]. Although several PAD inhibitors have been characterized, most of these compounds are somewhat ineffective [109].…”

The pro-inflammatory role of platelets in cancer

“…NETs have been shown to promote thrombosis both in tumorbearing mice and in cancer patients (49,61,65). Moreover, NETs in association with platelets contribute to kidney injury in mice with cancer (60,66). This effect was associated with vessel occlusion and could be suppressed by removal of NETs by treatment with DNase I or by prevention of de novo NET formation using an inhibitor of the enzyme peptidylarginine deiminase 4 (PAD4).…”