Acute kidney injury (AKI) has high incidence and mortality rates. Present treatments are mostly symptomatic and cause side effects due to systemic distribution; thus, targeted kidney drug delivery is desired. Transmembrane kidney injury molecule-1 (KIM1) is expressed at low levels in normal kidneys but markedly up-regulated following injury, making it an ideal marker/target for injured kidneys. Here, assisted by AlphaFold, we constructed a library of 1885 peptides that target the extracellular Ig V domain of KIM1 based on interacting fragments from 47 potential KIM1 binding proteins followed by systemic optimization according to their binding energies with KIM1. Experimental validation of top candidates (TKP 1-... More
Acute kidney injury (AKI) has high incidence and mortality rates. Present treatments are mostly symptomatic and cause side effects due to systemic distribution; thus, targeted kidney drug delivery is desired. Transmembrane kidney injury molecule-1 (KIM1) is expressed at low levels in normal kidneys but markedly up-regulated following injury, making it an ideal marker/target for injured kidneys. Here, assisted by AlphaFold, we constructed a library of 1885 peptides that target the extracellular Ig V domain of KIM1 based on interacting fragments from 47 potential KIM1 binding proteins followed by systemic optimization according to their binding energies with KIM1. Experimental validation of top candidates (TKP 1-5) demonstrated that TKP 4 efficiently targeted injured renal cells/kidneys, with its specificity demonstrated in KIM1 knockout cells/mice. TKP 4-decorating liposomes were loaded with nystatin, a renal-protective compound with systemic side effects, and efficiently targeted injured mouse kidneys and alleviated AKI. This work establishes a virtual platform to screen/identify drug delivery candidates with broad research/therapeutic potentials.
