Pulsed ultrasound targeted to the spleen mitigates against kidney injury and promotes kidney repair.

Acute kidney injury (AKI) is a devastating condition with major complications including death and, in some cases, progression to chronic kidney disease (CKD). We have previously shown that pulsed ultrasound (pUS) can reduce kidney ischemia-reperfusion injury (IRI) by activating the cholinergic anti-inflammatory pathway. The efficacy of a spleen-targeted pUS regimen in AKI of other etiologies and its long-term impact are unclear. Using a new spleen-targeted US approach, pUS was delivered to male mice 24 h before folic acid (FA), lipopolysaccharide, or bilateral kidney IRI. Mice were monitored and assessed for markers of inflammation, renal function, and kidney fibrosis. When compared with sham, mice that received spleen-targeted pUS had reduced plasma TNFα and blood urea nitrogen (BUN) after sepsis-associated AKI, reduced plasma creatinine, and BUN after kidney IRI and reduced plasma creatinine, BUN, and kidney fibrosis after FA administration. pUS-treated mice displayed reduced myeloid cell infiltration to the kidneys after FA and IRI. In sham-treated mice, markers associated with ongoing maladaptive repair including Sox9, Wnt2, and Wnt4 were increased on day 14 after FA in comparison with pUS-treated mice. These data demonstrate that pulsed ultrasound of the spleen is a novel, safe, and effective therapy for the prevention of AKI of multiple etiologies and the subsequent development of CKD. Findings from this study are critical for advancing human translation of ultrasound as a preventative measure for AKI and CKD.NEW & NOTEWORTHY We developed a safe and effective pulsed ultrasound (pUS) protocol targeting the mouse spleen to block inflammation and reduce AKI of multiple etiologies. By using a model of the AKI to CKD transition, we demonstrated the long-term benefits of pUS. The findings of these studies will be used to advance the human translation of spleen-targeted US as a preventative measure for AKI and CKD.