Chronic kidney disease amplifies severe kidney injury and mortality in a mouse model of skin arsenical exposure.

In previously published work, we elucidated the role of cutaneous arsenical exposure in promoting acute kidney injury (AKI) in adult healthy mice. Here, we determine whether preexisting chronic kidney disease (CKD) increases the severity of AKI. Following exposure to aristolochic acid (AA) (a nephrotoxic phytochemical in humans), mice manifested classical markers of CKD, including robust interstitial fibrosis and loss in kidney function. Skin challenge with phenylarsine oxide (PAO), a surrogate for warfare arsenicals, led to significantly worse kidney injury, as evidenced by tubulointerstitial fibrosis, glomerulosclerosis, a persistent loss of estimated glomerular filtration rate, and mortality in AA-induced CKD mice compared with mice without CKD. These PAO-challenged CKD mice exhibited enhanced production of serum/urine neutrophil gelatinase-associated lipocalin and a significant rise in serum creatinine along with histological markers of kidney injury, including brush border loss, tubular atrophy, cast formation, glomerular injury, and interstitial inflammatory cell infiltration. Serum cytokines IL-4, IL-6, IFN-γ, IL-12p70, TNF-α, and IL-18 significantly elevated in CKD mice following PAO exposure when compared with animals exposed to PAO alone. Furthermore, we found increased TUNEL-positive tubular cells in the kidneys of CKD mice following PAO exposure, suggesting enhanced PAO-mediated cell death in CKD mice. Mechanistically, we determined that DNA damage-regulated p53 signaling was a major mediator of cellular responses to PAO in CKD mice. In summary, our data demonstrate that CKD significantly increased the severity of AKI following exposure to arsenicals and suggest that human populations with preexisting CKD could be highly susceptible to arsenical-mediated kidney injury and associated morbidity and mortality.