Kidney released circulating osteopontin are identified as a novel Acute Kidney Injury (AKI)-Acute Lung Injury (ALI) mediator. Osteopontins are a key causal mediator of AKI induced remote ALI with respiratory failure. Circulating osteopontins that mediate the induction of AKI-ALI are released from the inured kidney. They are released from kidney tubule cells damaged bylung endothelial leakage, inflammation, and respiratory failure. 

It has been shown in studies that osteopontin serum levels are raised in patients with AKI and correlate with kidney injury. Interestingly, osteopontin serum levels are lower with only one injured transplant kidneys, as compared to the bilateral IRI model, where two kidneys are injured. Kidneys are definitely identified as the source of osteopontin during the development of ALI after AKI. From a treatment point of view, inhibition of osteopontins through pharmacological or genetic means can prevent AKI-ALI.

Reference: Khamissi FZ, Ning L, Kefaloyianni E, Dun H, et al. Sci Adv. 2022; 8: eabm5900.