Secondary biliary cirrhosis in the rat is prevented by decreasing NF-κ B nuclear translocation and TGF-β expression using allopurinol, an inhibitor of xanthine oxidase

2012 ◽  
Vol 90 (11) ◽  
pp. 1469-1478 ◽  
Author(s):  
Liseth R. Aldaba-Muruato ◽  
Mario G. Moreno ◽  
Elisa Hernández-Mercado ◽  
Mineko Shibayama ◽  
Pablo Muriel
Keyword(s):  
Oxidative Stress ◽  
Xanthine Oxidase ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Active Form ◽  
Transforming Growth Factor Β ◽  
Biliary Cirrhosis ◽  
Common Bile Duct Ligation ◽  
Experimental Cirrhosis ◽  
Duct Ligation

Allopurinol is an inhibitor of xanthine oxidase (XO), and XO is an enzyme that generates great amounts of reactive oxygen species. The aim of this work was to evaluate the efficacy of allopurinol to prevent experimental cirrhosis. Fibrosis and cirrhosis were induced by common bile duct ligation (BDL) for 4 weeks in rats. Animals were divided into 4 groups: sham-operated rats (SHAM); BDL group; BDL plus allopurinol (100 mg·kg–1, p.o.), and SHAM plus allopurinol treatment. Alanine aminotransferase, γ-glutamyl transpeptidase, and alkaline phosphatase were increased in BDL rats but were preserved normal by allopurinol. XO activity was prevented by allopurinol; however, lipophilic and hydrophilic oxidative stress was not prevented by the drug. Allopurinol partially suppresses nuclear factor-κB (NF-κB) nuclear translocation and transforming growth factor-β (TGF-β) expression, and increased the active form of matrix metalloproteinase-13 (MMP-13). Moreover, collagen production induced by BDL was partially but significantly reduced by allopurinol. These findings suggest that allopurinol possesses a hepatoprotective effect probably by modulating proteins such as NF-κB, TGF-β, and MMP-13, helping to protect against liver damage induced by chronic cholestasis and a mechanism independent of oxidative stress.

scholarly journals Quercetin Treatment Ameliorates Systemic Oxidative Stress in Cirrhotic Rats

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Emanuelle Kerber Vieira ◽  
Silvia Bona ◽  
Fábio Cangeri Di Naso ◽  
Marilene Porawski ◽  
Juliana Tieppo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bile Duct ◽  
Thiobarbituric Acid ◽  
Biliary Cirrhosis ◽  
Thiobarbituric Acid Reactive Substances ◽  
Common Bile Duct Ligation ◽  
Systemic Oxidative Stress ◽  
Duct Ligation ◽  
Secondary Biliary Cirrhosis ◽  
Quercetin Treatment

Our aim was to investigate whether the antioxidant quercetin protects against liver injury and ameliorates the systemic oxidative stress in rats with common bile duct ligation. Secondary biliary cirrhosis was induced through 28 days of bile duct obstruction. Animals received quercetin (Q) after 14 days of obstruction. Groups of control (CO) and cirrhotic (CBDL) animals received a daily 50 mg/kg body weight i.p. injection of quercetin (CO + Q; CBDL + Q) or vehicle (CO; CBDL). Quercetin corrected the reduction in superoxide dismutase (SOD), catalase CAT, and glutathione peroxidase GPx activities and prevented the increase of thiobarbituric acid reactive substances (TBARS), aminotransferases, and alkaline phosphatase in cirrhotic animals. Quercetin administration also corrected the reduced total nitrate concentration in the liver and prevented liver fibrosis and necrosis. These effects suggest that quercetin might be a useful agent to preserve liver function and prevent systemic oxidative stress.

Upregulation of osteopontin expression is involved in the development of nonalcoholic steatohepatitis in a dietary murine model

2004 ◽  
Vol 287 (1) ◽  
pp. G264-G273 ◽  
Author(s):  
Atul Sahai ◽  
Padmini Malladi ◽  
Hector Melin-Aldana ◽  
Richard M. Green ◽  
Peter F. Whitington
Keyword(s):  
Oxidative Stress ◽  
Mrna Expression ◽  
Nonalcoholic Steatohepatitis ◽  
Transforming Growth Factor ◽  
Control Diet ◽  
Transforming Growth Factor Β ◽  
Collagen I ◽  
Tnf Α ◽  
Th1 Cytokine

The pathogenesis of nonalcoholic steatohepatitis (NASH) is poorly defined. Feeding mice a diet deficient in methionine and choline (MCD diet) induces experimental NASH. Osteopontin (OPN) is a Th1 cytokine that plays an important role in several fibroinflammatory diseases. We examined the role of OPN in the development of experimental NASH. A/J mice were fed MCD or control diet for up to 12 wk, and serum alanine aminotransferase (ALT), liver histology, oxidative stress, and the expressions of OPN, TNF-α, and collagen I were assessed at various time points. MCD diet-fed mice developed hepatic steatosis starting after 1 wk and inflammation by 2 wk; serum ALT increased from day 3. Hepatic collagen I mRNA expression increased during 1–4 wk, and fibrosis appeared at 8 wk. OPN protein expression was markedly increased on day 1 of MCD diet and persisted up to 8 wk, whereas OPN mRNA expression was increased at week 4. TNF-α expression was increased from day 3 to 2 wk, and evidence of oxidative stress did not appear until 8 wk. Increased expression of OPN was predominantly localized in hepatocytes. Hepatocytes in culture also produced OPN, which was stimulated by transforming growth factor-β and TNF-α. Moreover, MCD diet-induced increases in serum ALT levels, hepatic inflammation, and fibrosis were markedly reduced in OPN−/− mice when compared with OPN+/+ mice. In conclusion, our results demonstrate an upregulation of OPN expression early in the development of steatohepatitis and suggest an important role for OPN in signaling the onset of liver injury and fibrosis in experimental NASH.

scholarly journals A mechanism of suppression of TGF–β/SMAD signaling by NF-κB/RelA

2000 ◽  
Vol 14 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Markus Bitzer ◽  
Gero von Gersdorff ◽  
Dan Liang ◽  
Alfredo Dominguez-Rosales ◽  
Amer A. Beg ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Transforming Growth Factor Β ◽  
Nuclear Factor Κb ◽  
Transcriptional Responses ◽  
Smad Signaling ◽  
Antisense Mrna ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

A number of pathogenic and proinflammatory stimuli, and the transforming growth factor-β (TGF-β) exert opposing activities in cellular and immune responses. Here we show that the RelA subunit of nuclear factor κB (NF-κB/RelA) is necessary for the inhibition of TGF-β-induced phosphorylation, nuclear translocation, and DNA binding of SMAD signaling complexes by tumor necrosis factor-α (TNF-α). The antagonism is mediated through up-regulation of Smad7 synthesis and induction of stable associations between ligand-activated TGF-β receptors and inhibitory Smad7. Down-regulation of endogenous Smad7 by expression of antisense mRNA releases TGF-β/SMAD-induced transcriptional responses from suppression by cytokine-activated NF-κB/RelA. Following stimulation with bacterial lipopolysaccharide (LPS), or the proinflammatory cytokines TNF-α and interleukin-1β (IL-1β, NF-κB/RelA induces Smad7 synthesis through activation of Smad7 gene transcription. These results suggest a mechanism of suppression of TGF-β/SMAD signaling by opposing stimuli mediated through the activation of inhibitory Smad7 by NF-κB/RelA.

scholarly journals CIRRHOSIS INDUCES APOPTOSIS IN RENAL TISSUE THROUGH INTRACELLULAR OXIDATIVE STRESS

2015 ◽  
Vol 52 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Keli Cristina Simões da SILVEIRA ◽  
Cassiana Macagnan VIAU ◽  
Josiane Raskopf COLARES ◽  
Jenifer SAFFI ◽  
Norma Possa MARRONI ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Membrane Potential ◽  
Bile Duct ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Bile Duct Ligation ◽  
Decompensated Cirrhosis ◽  
Biliary Cirrhosis ◽  
Duct Ligation

Background Renal failure is a frequent and serious complication in patients with decompensated cirrhosis. Objectives We aimed to evaluate the renal oxidative stress, cell damage and impaired cell function in animal model of cirrhosis. Methods Secondary biliary cirrhosis was induced in rats by ligation of the common bile duct. We measured TBARS, ROS and mitochondrial membrane potential in kidney as markers of oxidative stress, and activities of the antioxidant enzymes. Relative cell viability was determined by trypan blue dye-exclusion assay. Annexin V-PE was used with a vital dye, 7-AAD, to distinguish apoptotic from necrotic cells and comet assay was used for determined DNA integrity in single cells. Results In bile duct ligation animals there was significant increase in the kidney lipoperoxidation and an increase of the level of intracellular ROS. There was too an increase in the activity of all antioxidant enzymes evaluated in the kidney. The percentage viability was above 90% in the control group and in bile duct ligation was 64.66% and the dominant cell death type was apoptosis. DNA damage was observed in the bile duct ligation. There was a decreased in the mitochondrial membrane potential from 71.40% ± 6.35% to 34.48% ± 11.40% in bile duct ligation. Conclusions These results indicate that intracellular increase of ROS cause damage in the DNA and apoptosis getting worse the renal function in cirrhosis.

scholarly journals Kelch-like protein 42 is a profibrotic ubiquitin E3 ligase involved in systemic sclerosis

2020 ◽  
Vol 295 (13) ◽  
pp. 4171-4180 ◽  
Author(s):  
Travis B. Lear ◽  
Karina C. Lockwood ◽  
Mads Larsen ◽  
Ferhan Tuncer ◽  
Jason R. Kennerdell ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
E3 Ligase ◽  
Transforming Growth Factor Β ◽  
Lung Fibroblasts ◽  
Regulatory Subunit ◽  
Connective Tissues ◽  
E3 Ligases ◽  
Ubiquitin E3 Ligase

Systemic scleroderma (SSc) is an autoimmune disease that affects over 2.5 million people globally. SSc results in dysfunctional connective tissues with excessive profibrotic signaling, affecting skin, cardiovascular, and particularly lung tissue. Over three-quarters of individuals with SSc develop pulmonary fibrosis within 5 years, the main cause of SSc mortality. No approved medicines to manage lung SSc currently exist. Recent research suggests that profibrotic signaling by transforming growth factor β (TGF-β) is directly tied to SSc. Previous studies have also shown that ubiquitin E3 ligases potently control TGF-β signaling through targeted degradation of key regulatory proteins; however, the roles of these ligases in SSc–TGF-β signaling remain unclear. Here we utilized primary SSc patient lung cells for high-throughput screening of TGF-β signaling via high-content imaging of nuclear translocation of the profibrotic transcription factor SMAD family member 2/3 (SMAD2/3). We screened an RNAi library targeting ubiquitin E3 ligases and observed that knockdown of the E3 ligase Kelch-like protein 42 (KLHL42) impairs TGF-β–dependent profibrotic signaling. KLHL42 knockdown reduced fibrotic tissue production and decreased TGF-β–mediated SMAD activation. Using unbiased ubiquitin proteomics, we identified phosphatase 2 regulatory subunit B'ϵ (PPP2R5ϵ) as a KLHL42 substrate. Mechanistic experiments validated ubiquitin-mediated control of PPP2R5ϵ stability through KLHL42. PPP2R5ϵ knockdown exacerbated TGF-β–mediated profibrotic signaling, indicating a role of PPP2R5ϵ in SSc. Our findings indicate that the KLHL42–PPP2R5ϵ axis controls profibrotic signaling in SSc lung fibroblasts. We propose that future studies could investigate whether chemical inhibition of KLHL42 may ameliorate profibrotic signaling in SSc.

scholarly journals Albuminuria induces a proinflammatory and profibrotic response in cortical collecting ducts via the 24p3 receptor

2013 ◽  
Vol 305 (7) ◽  
pp. F1053-F1063 ◽  
Author(s):  
Eva Dizin ◽  
Udo Hasler ◽  
Stellor Nlandu-Khodo ◽  
Marc Fila ◽  
Isabelle Roth ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Collecting Duct ◽  
Transforming Growth Factor Β ◽  
Luciferase Reporter ◽  
Lipocalin 2 ◽  
Luciferase Reporter Gene ◽  
Puromycin Aminonucleoside ◽  
Gene Assay ◽  
Albumin Endocytosis

Albuminuria is strongly associated with progressive kidney tubulo-interstitial damage and chronic kidney disease (CKD) progression. In proteinuric nephropathies, albumin reabsorption by the proximal tubule is saturated and the distal nephron is exposed to high concentrations of luminal albumin that may produce adverse effects. Since proximal tubular cells exposed to albuminuria exhibit a proinflammatory and profibrotic response, we assessed the effect of albuminuria in the collecting duct (CD). With the use of kidney sections and isolated cortical CDs (CCDs) from puromycin-aminonucleoside-induced nephrotic rats (PAN rats) exhibiting proteinuria, immunofluorescence microscopy revealed internalized albumin in CD cells. In these proteinuric rats, increased expression levels of cytokines and profibrotic signaling markers were detected in isolated CCDs and bands of inflammatory fibrosis could be observed around CDs. Albumin endocytosis was confirmed by FITC-albumin uptake in cultured murine CCD (mCCDcl1) cells. Exposure of mCCDcl1 cells to albumin induced NF-κB activation as assessed by luciferase reporter gene assay, nuclear translocation of NF-κB p65 subunit, and increased NF-κB target gene expression. Moreover, albuminuria-like condition results in transforming growth factor-β1 (TGF-β1) overexpression and the upregulation of profibrotic signaling markers such as Snail or vimentin via an autocrine mechanism. In mCCDcl1 cells, neutrophil gelatinase-associated lipocalin (NGAL)/lipocalin-2/24p3 receptor (24p3R) mediates albumin endocytosis as well as activation of NF-κB and TGF-β1 signaling pathways. Therefore, CD may play a key role in initiation and/or progression of inflammation and fibrosis in response to proteinuria.

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