The archaeal Dps nanocage targets kidney proximal tubules via glomerular filtration
Masaki Uchida, … , Trevor Douglas, Takashi Hato
Masaki Uchida, … , Trevor Douglas, Takashi Hato
Published August 19, 2019
Citation Information: J Clin Invest. 2019;129(9):3941-3951. https://doi.org/10.1172/JCI127511.
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The archaeal Dps nanocage targets kidney proximal tubules via glomerular filtration

Abstract

Nature exploits cage-like proteins for a variety of biological purposes, from molecular packaging and cargo delivery to catalysis. These cage-like proteins are of immense importance in nanomedicine due to their propensity to self-assemble from simple identical building blocks to highly ordered architecture and the design flexibility afforded by protein engineering. However, delivery of protein nanocages to the renal tubules remains a major challenge because of the glomerular filtration barrier, which effectively excludes conventional size nanocages. Here, we show that DNA-binding protein from starved cells (Dps) — the extremely small archaeal antioxidant nanocage — is able to cross the glomerular filtration barrier and is endocytosed by the renal proximal tubules. Using a model of endotoxemia, we present an example of the way in which proximal tubule–selective Dps nanocages can limit the degree of endotoxin-induced kidney injury. This was accomplished by amplifying the endogenous antioxidant property of Dps with addition of a dinuclear manganese cluster. Dps is the first-in-class protein cage nanoparticle that can be targeted to renal proximal tubules through glomerular filtration. In addition to its therapeutic potential, chemical and genetic engineering of Dps will offer a nanoplatform to advance our understanding of the physiology and pathophysiology of glomerular filtration and tubular endocytosis.

Authors

Masaki Uchida, Bernhard Maier, Hitesh Kumar Waghwani, Ekaterina Selivanovitch, S. Louise Pay, John Avera, EJun Yun, Ruben M. Sandoval, Bruce A. Molitoris, Amy Zollman, Trevor Douglas, Takashi Hato

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Figure 3

MnDps reduces endotoxin-induced renal tissue damage.

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MnDps reduces endotoxin-induced renal tissue damage. (A) Serum creatinin...
(A) Serum creatinine levels 24 hours after 5 mg/kg LPS i.p. with 18 mg/kg unmodified Dps, MnDps, or PBS vehicle i.v. Administration of Dps, MnDps, or vehicle was done via tail vein immediately before LPS i.p. injection. *P < 0.05 vs. LPS+vehicle or LPS+Dps, 1-way ANOVA followed by pairwise t tests with corrections for multiple testing using the Benjamini and Hochberg procedure. n = 8 per condition. Error bars show SD. (B and C) Kidney tissue Kim1/Havcr1 and Ngal/Lcn2 levels under indicated conditions 24 hours after 5 mg/kg LPS i.p., as determined with quantitative PCR. n = 4–5 per condition as depicted with dot plots. *P < 0.05 vs. LPS+vehicle or LPS+Dps. (D) Total catalase activity levels (endogenous and exogenous catalase activities) are shown for indicated conditions. *P < 0.05 vs. LPS 4 hours + vehicle. (E) Endogenous protein catalase levels were determined by Western blot. LPS, 4 hours; catalase, MW, 60 kDa; actin, 42 kDa, n = 3 per condition. (F–H) Staining for 8-OHdG, a marker of oxidative stress/oxidized DNA and RNA, under indicated conditions (LPS 4 hours). Insets provide enlarged views, ×40. n = 3 per condition. (I) Mice were treated under indicated conditions, and kidney tissues were fractionated for cytoplasm and nuclei and analyzed by Western blot for Nrf2 (MW, ~100 kDa). MnDps treatment reduced nuclear translocation of Nrf2 as compared with vehicle control after LPS challenge for indicated durations. (J) Western blot analysis of kidney tissues for Hmox1 under indicated conditions (MW, 32 kDa). Induction of Hmox1 was limited with MnDps treatment.