Experimental Nonalcoholic Steatohepatitis and Liver Fibrosis Are Ameliorated by Pharmacologic Activation of Nrf2 (NF-E2 p45-Related Factor 2)

• Published in: Cellular and molecular gastroenterology and hepatology Vol. 5; no. 3; pp. 367 - 398
• Main Authors: Sharma, Ritu S, Harrison, David J, Kisielewski, Dorothy, Cassidy, Diane M, McNeilly, Alison D, Gallagher, Jennifer R, Walsh, Shaun V, Honda, Tadashi, McCrimmon, Rory J, Dinkova-Kostova, Albena T, Ashford, Michael L.J, Dillon, John F, Hayes, John D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2018; Elsevier
• Subjects: Gastroenterology and Hepatology; NASH; Nrf2; Original Research; TBE-31; TXN1; NAS; acetyl-CoA carboxylase alpha; sterol regulatory element-binding protein-1c; GTT; NF-E2 p45-related factor 2; cyclooxygenase-2; oxidized glutathione; LXRα; insulin tolerance test; cluster of differentiation 36; alpha smooth muscle actin; AP-1; MPO; eIf2α; nonalcoholic steatohepatitis; α-SMA; c-Jun N-terminal kinase 1; high-fat; UPR; CHOP; glutathione S-transferase Alpha-4; CPT1A; ACOT7; DGAT2; H&E; qRT-PCR; collagen, type I, alpha-1; carbohydrate-responsive element-binding protein; PPARα; PPARγ; ACLY; RC; unfolded protein response; high-fat diet with 55% fructose in drinking water; fatty acid synthase; p58 IPK; apolipoprotein B; ATF6; ATF4; C/EBP; inhibitor of NF-κB; non-alcoholic fatty liver disease; methionine- and choline-deficient; nitric oxide synthase-2; MTTP; HFFr; liver X receptor α; TBE-31; ACACA; carnitine palmitoyltransferase 1a; Kelch-like ECH-associated protein-1; Nrf2; SCAD; COX2; HMOX1; HF55Fr; SFN; adipose differentiation-related protein; ApoB; inositol requiring kinase-1α; hematoxylin and eosin; GSSG; XBP1; GSTM1; glutamate-cysteine ligase catalytic; IKK; thioredoxin reductase-1; NASH; PRDX6; SREBP-1c; MCD; COL1A1; 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid; GCLC; FASN; tumor necrosis factor-α; Keap1; small heterodimer partner; GCLM; solute carrier family 7 member 11; sulforaphane; pyruvate tolerance test; DMSO; ITT; C/EBP homologous protein; SLC7A11; IκB kinase; glutathione peroxidase-2; NF-κB; monocyte chemotactic protein-1; activator protein 1; peroxiredoxin 6; p58 inhibitor of the PKR kinase; SHP; CD36; SCD1; transforming growth factor beta-1; PRK-like endoplasmic reticulum kinase; catalase; GPX2; NAFLD activity score; protein disulfide isomerase; activating transcription factor-6; JNK1; activating transcription factor-4; heme oxygenase-1; diacylglycerol acyltransferase-2; PTGR1; ER; nuclear factor-κB; CDDO; ACOX2; CAT; high-fat diet with fructose in drinking water; PCR; ADRP; stearoyl-CoA desaturase-1; FXR; MCP-1; NAFLD; glucose tolerance test; ATP citrate lyase; acetyl-CoA oxidase 2; HF30Fr; microsomal triglyceride transfer protein; PARP; CCAAT/enhancer-binding protein; PERK; carboxylesterase 1g; thioredoxin-1; eukaryotic translation initiation factor 2A; regular chow; IκB; BCL-2; PTT; dimethyl sulfoxide; reduced glutathione; PDI; short-chain acyl-CoA dehydrogenase; GSH; polymerase chain reaction; high-fat diet with 30% fructose in drinking water; glutamate-cysteine ligase modifier; mitochondrial glycerol-3-phosphate acetyltransferase; NQO1; NOS2; farnesoid X receptor; TXNRD1; acetyl-CoA thioesterase 7; BIP; myeloperoxidase; X-box binding protein-1; NAD(P)H:quinone oxidoreductase 1; ChREBP; GSTA4; TNF-α; binding immunoglobulin protein; CES1G; IRE1α; MGPAT; TGFβ; poly ADP ribose polymerase; quantitative reverse transcriptase PCR; glutathione S-transferase Mu-1; peroxisome proliferator-activated receptor γ; endoplasmic reticulum; HF; prostaglandin reductase-1; B-cell lymphoma; peroxisome proliferator-activated receptor α; p58IPK; MGPAT, mitochondrial glycerol-3-phosphate acetyltransferase; SREBP-1c, sterol regulatory element-binding protein-1c; PTT, pyruvate tolerance test; SLC7A11, solute carrier family 7 member 11; DGAT2, diacylglycerol acyltransferase-2; NAS, NAFLD activity score; NOS2, nitric oxide synthase-2; CDDO, 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid; MPO, myeloperoxidase; CES1G, carboxylesterase 1g; ADRP, adipose differentiation-related protein; NAFLD, non-alcoholic fatty liver disease; SCD1, stearoyl-CoA desaturase-1; ATF4, activating transcription factor-4; XBP1, X-box binding protein-1; H&E, hematoxylin and eosin; NASH, nonalcoholic steatohepatitis; BCL-2, B-cell lymphoma; NQO1, NAD(P)H:quinone oxidoreductase 1; UPR, unfolded protein response; HF30Fr, high-fat diet with 30% fructose in drinking water; CAT, catalase; Keap1, Kelch-like ECH-associated protein-1; qRT-PCR, quantitative reverse transcriptase PCR; IκB, inhibitor of NF-κB; PARP, poly ADP ribose polymerase; Nrf2, NF-E2 p45-related factor 2; p58IPK, p58 inhibitor of the PKR kinase; GSSG, oxidized glutathione; TXN1, thioredoxin-1; GTT, glucose tolerance test; GSTM1, glutathione S-transferase Mu-1; PERK, PRK-like endoplasmic reticulum kinase; GCLM, glutamate-cysteine ligase modifier; FASN, fatty acid synthase; LXRα, liver X receptor α; α-SMA, alpha smooth muscle actin; GSTA4, glutathione S-transferase Alpha-4; PTGR1, prostaglandin reductase-1; MTTP, microsomal triglyceride transfer protein; COX2, cyclooxygenase-2; PCR, polymerase chain reaction; IRE1α, inositol requiring kinase-1α; CPT1A, carnitine palmitoyltransferase 1a; GSH, reduced glutathione; SFN, sulforaphane; ApoB, apolipoprotein B; SCAD, short-chain acyl-CoA dehydrogenase; IKK, IκB kinase; HF, high-fat; GPX2, glutathione peroxidase-2; GCLC, glutamate-cysteine ligase catalytic; PPARα, peroxisome proliferator-activated receptor α; PPARγ, peroxisome proliferator-activated receptor γ; PDI, protein disulfide isomerase; HF55Fr, high-fat diet with 55% fructose in drinking water; MCD, methionine- and choline-deficient; AP-1, activator protein 1; ATF6, activating transcription factor-6; SHP, small heterodimer partner; BIP, binding immunoglobulin protein; C/EBP, CCAAT/enhancer-binding protein; HMOX1, heme oxygenase-1; ITT, insulin tolerance test; ACACA, acetyl-CoA carboxylase alpha; ACOT7, acetyl-CoA thioesterase 7; CHOP, C/EBP homologous protein; TGFβ, transforming growth factor beta-1; JNK1, c-Jun N-terminal kinase 1; FXR, farnesoid X receptor; TXNRD1, thioredoxin reductase-1; PRDX6, peroxiredoxin 6; HFFr, high-fat diet with fructose in drinking water; ACLY, ATP citrate lyase; TNF-α, tumor necrosis factor-α; RC, regular chow; NF-κB, nuclear factor-κB; DMSO, dimethyl sulfoxide; COL1A1, collagen, type I, alpha-1; eIf2α, eukaryotic translation initiation factor 2A; CD36, cluster of differentiation 36; ER, endoplasmic reticulum; MCP-1, monocyte chemotactic protein-1; ChREBP, carbohydrate-responsive element-binding protein; ACOX2, acetyl-CoA oxidase 2
• ISSN: 2352-345X; 2352-345X
• DOI: 10.1016/j.jcmgh.2017.11.016

Background & Aims Nonalcoholic steatohepatitis (NASH) is associated with oxidative stress. We surmised that pharmacologic activation of NF-E2 p45-related factor 2 (Nrf2) using the acetylenic tricyclic bis(cyano enone) TBE-31 would suppress NASH because Nrf2 is a transcriptional master regulator of intracellular redox homeostasis. Methods Nrf2 +/+ and Nrf2 -/- C57BL/6 mice were fed a high-fat plus fructose (HFFr) or regular chow diet for 16 weeks or 30 weeks, and then treated for the final 6 weeks, while still being fed the same HFFr or regular chow diets, with either TBE-31 or dimethyl sulfoxide vehicle control. Measures of whole-body glucose homeostasis, histologic assessment of liver, and biochemical and molecular measurements of steatosis, endoplasmic reticulum (ER) stress, inflammation, apoptosis, fibrosis, and oxidative stress were performed in livers from these animals. Results TBE-31 treatment reversed insulin resistance in HFFr-fed wild-type mice, but not in HFFr-fed Nrf2-null mice. TBE-31 treatment of HFFr-fed wild-type mice substantially decreased liver steatosis and expression of lipid synthesis genes, while increasing hepatic expression of fatty acid oxidation and lipoprotein assembly genes. Also, TBE-31 treatment decreased ER stress, expression of inflammation genes, and markers of apoptosis, fibrosis, and oxidative stress in the livers of HFFr-fed wild-type mice. By comparison, TBE-31 did not decrease steatosis, ER stress, lipogenesis, inflammation, fibrosis, or oxidative stress in livers of HFFr-fed Nrf2-null mice. Conclusions Pharmacologic activation of Nrf2 in mice that had already been rendered obese and insulin resistant reversed insulin resistance, suppressed hepatic steatosis, and mitigated against NASH and liver fibrosis, effects that we principally attribute to inhibition of ER, inflammatory, and oxidative stress.