Anti–microRNA-21 oligonucleotides prevent Alport nephropathy progression by stimulating metabolic pathways
Ivan G. Gomez, … , B. Nelson Chau, Jeremy S. Duffield
Ivan G. Gomez, … , B. Nelson Chau, Jeremy S. Duffield
Published November 21, 2014
Citation Information: J Clin Invest. 2015;125(1):141-156. https://doi.org/10.1172/JCI75852.
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Research Article Nephrology

Anti–microRNA-21 oligonucleotides prevent Alport nephropathy progression by stimulating metabolic pathways

Abstract

MicroRNA-21 (miR-21) contributes to the pathogenesis of fibrogenic diseases in multiple organs, including the kidneys, potentially by silencing metabolic pathways that are critical for cellular ATP generation, ROS production, and inflammatory signaling. Here, we developed highly specific oligonucleotides that distribute to the kidney and inhibit miR-21 function when administered subcutaneously and evaluated the therapeutic potential of these anti–miR-21 oligonucleotides in chronic kidney disease. In a murine model of Alport nephropathy, miR-21 silencing did not produce any adverse effects and resulted in substantially milder kidney disease, with minimal albuminuria and dysfunction, compared with vehicle-treated mice. miR-21 silencing dramatically improved survival of Alport mice and reduced histological end points, including glomerulosclerosis, interstitial fibrosis, tubular injury, and inflammation. Anti–miR-21 enhanced PPARα/retinoid X receptor (PPARα/RXR) activity and downstream signaling pathways in glomerular, tubular, and interstitial cells. Moreover, miR-21 silencing enhanced mitochondrial function, which reduced mitochondrial ROS production and thus preserved tubular functions. Inhibition of miR-21 was protective against TGF-β–induced fibrogenesis and inflammation in glomerular and interstitial cells, likely as the result of enhanced PPARα/RXR activity and improved mitochondrial function. Together, these results demonstrate that inhibition of miR-21 represents a potential therapeutic strategy for chronic kidney diseases including Alport nephropathy.

Authors

Ivan G. Gomez, Deidre A. MacKenna, Bryce G. Johnson, Vivek Kaimal, Allie M. Roach, Shuyu Ren, Naoki Nakagawa, Cuiyan Xin, Rick Newitt, Shweta Pandya, Tai-He Xia, Xueqing Liu, Dorin-Bogdan Borza, Monica Grafals, Stuart J. Shankland, Jonathan Himmelfarb, Didier Portilla, Shiguang Liu, B. Nelson Chau, Jeremy S. Duffield

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Figure 6

Anti–miR-21 administration recapitulates miR-21 gene deficiency by preventing miR-21–mediated suppression of the PPARα FA metabolism and mitochondrial biogenesis pathways in the kidney proximal epithelium.

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Anti–miR-21 administration recapitulates miR-21 gene deficiency by preve...
(A–C) Graphs of qPCR results showing the effect of miR-21 gene deficiency on PPARα lipid metabolism pathway transcriptional responses (Ppara, Cpt1, and Mcad) in primary cultured mouse PTECs in resting conditions or in response to active TGF-β–induced cell stress. (D) Graph of Ppargc1a levels in steady-state and response to TGF-β stress in miR21-deficient PTECs. (E) Graph of the effect of TGF-β on mitochondrial ATP generation by mouse PTECs in the absence of miR21. (F) Representative images of MitoTracker-labeled PTECs showing increased mitochondrial density in miR21-deficient PTECs, particularly in response to TGF-β stress. (G) Western blot showing levels of the peroxisome protein PMP70 in mouse PTECs at rest and in response to TGF-β stress. (H–I) The effect of anti–miR-21 treatment of mouse PTECs from Col4a3–/– mouse kidneys on Ppara expression and mitochondrial ATP generation (J–L) Graphs showing the effect of anti–miR-21 treatment on human primary PTEC levels of PPARA or PPARGC1A or mitochondrial ATP production under resting or TGF-β stress conditions. *P < 0.05; **P < 0.01, Mann-Whitney U test. n = 3–5/group. Scale bars: 25 μm.