ASK1 contributes to fibrosis and dysfunction in models of kidney disease
John T. Liles, … , Agnes B. Fogo, David G. Breckenridge
John T. Liles, … , Agnes B. Fogo, David G. Breckenridge
Published July 19, 2018
Citation Information: J Clin Invest. 2018;128(10):4485-4500. https://doi.org/10.1172/JCI99768.
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Research Article Nephrology Therapeutics

ASK1 contributes to fibrosis and dysfunction in models of kidney disease

Abstract

Oxidative stress is an underlying component of acute and chronic kidney disease. Apoptosis signal–regulating kinase 1 (ASK1) is a widely expressed redox-sensitive serine threonine kinase that activates p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase kinases, and induces apoptotic, inflammatory, and fibrotic signaling in settings of oxidative stress. We describe the discovery and characterization of a potent and selective small-molecule inhibitor of ASK1, GS-444217, and demonstrate the therapeutic potential of ASK1 inhibition to reduce kidney injury and fibrosis. Activation of the ASK1 pathway in glomerular and tubular compartments was confirmed in renal biopsies from patients with diabetic kidney disease (DKD) and was decreased by GS-444217 in several rodent models of kidney injury and fibrosis that collectively represented the hallmarks of DKD pathology. Treatment with GS-444217 reduced progressive inflammation and fibrosis in the kidney and halted glomerular filtration rate decline. Combination of GS-444217 with enalapril, an angiotensin-converting enzyme inhibitor, led to a greater reduction in proteinuria and regression of glomerulosclerosis. These results identify ASK1 as an important target for renal disease and support the clinical development of an ASK1 inhibitor for the treatment of DKD.

Authors

John T. Liles, Britton K. Corkey, Gregory T. Notte, Grant R. Budas, Eric B. Lansdon, Ford Hinojosa-Kirschenbaum, Shawn S. Badal, Michael Lee, Brian E. Schultz, Sarah Wise, Swetha Pendem, Michael Graupe, Laurie Castonguay, Keith A. Koch, Melanie H. Wong, Giuseppe A. Papalia, Dorothy M. French, Theodore Sullivan, Erik G. Huntzicker, Frank Y. Ma, David J. Nikolic-Paterson, Tareq Altuhaifi, Haichun Yang, Agnes B. Fogo, David G. Breckenridge

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Figure 4

GS-444217 inhibits activation of ASK1, p38, and JNK in rat kidney.

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GS-444217 inhibits activation of ASK1, p38, and JNK in rat kidney. (A an...
(A and C–F) A single oral dose of GS-444217 (30 mg/kg, n = 8) or vehicle (equal volume, n = 5) was administered to Sprague-Dawley rats, which were challenged 30 minutes later with auranofin (30 mg/kg, i.p.) to cause OS-induced activation of the ASK1 pathway. Kidney cortex samples were collected 30 minutes after auranofin administration. (A) Western blot analysis of renal cortex lysates showing p-ASK1, p-p38, and p-JNK levels after in vivo administration of vehicle, auranofin, or auranofin and 30 mg/kg GS-444217. Dot plots show p-ASK1, p-p38, and p-JNK levels normalized to IP90 loading control. (B) GS-444217 (10 mg/kg, n = 14, or 30 mg/kg, n = 12, p.o.) was administered to Sprague-Dawley rats. Plasma was collected from individual rats over the course of the dosing interval, and kidneys were collected at the end of the time course. Based on plasma concentrations of GS-444217 and the corresponding p-p38 signal in each kidney (measured by ELISA in renal cortex lysates), the in vivo EC50 of GS-444217 for inhibition of the renal ASK1 pathway was estimated to be 1.6 μM. (C–F) Relative mRNA expression of inflammatory cytokines (Il1b, Ccl2, and Cxcl2) and caspase activity were measured in kidneys of rats treated with vehicle, auranofin, or auranofin and 30 mg/kg GS-444217. RFU, relative fluorescence units. For A and C–F, data are mean ± SEM; *P < 0.01 vs. control, †P < 0.01 vs. auranofin (ANOVA with Bonferroni’s multiple-comparisons test).