Primary cirrhotic hepatocytes resist TGF$beta;-induced apoptosis through a ROS-dependent mechanism

Black, Dalliah M.; Bird, Mark A.; Samson, Charles M.; Lyman, Suzanne; Lange, Patty A.; Schrum, Laura W.; Qian, Ting; Lemasters, John J.; Brenner, David A.; Rippe, Richard A.; Behrns, Kevin E.

doi:10.1016/j.jhep.2004.02.031

Cited by 30 publications

(56 citation statements)

References 54 publications

(40 reference statements)

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“…The MPT was assessed by confocal microscopy with the dyes tetramethylrhodamine methyl ester (250 nM; TMRM, Molecular Probes) and calcein (1 μM Molecular Probes) as described previously [5]. Hepatocytes (1 × 10 6 in a 60 mm dish) plated on collagen-coated coverslips were loaded with the dyes for 20 minutes at 37°C, and then rinsed with PBS.…”

Section: Mitochondrial Permeability Transition (Mpt)mentioning

confidence: 99%

“…Typically, TGFβ causes hepatocyte MPT prior to apoptosis [5]. In these experiments, MPT was assessed by confocal microscopy using the dyes TMRM and calcein.…”

Section: Smad3 (−/−) Hepatocytes Resist Tgfβ-induced Apoptosismentioning

confidence: 99%

“…Both studies demonstrated that ROS generation was dependent on new protein synthesis. Other studies have demonstrated that early (90 minutes) activation of ROS is important for TGFβ-induced apoptosis [5]. However, no study has demonstrated the importance of Smad activation in ROS generation following TGFβ stimulation.…”

Section: Introductionmentioning

confidence: 98%

“…In vitro and in vivo studies have also shown that TGFβ controls hepatocyte growth directly by inducing apoptosis [2][3][4]. Furthermore, TGFβ-induced apoptosis occurs through ROS generation, the mitochondrial permeability transition (MPT), and caspase activation [5]. Moreover, Smad3-dependent cleavage of the mitochondrial, pro-apoptotic protein, BAD, results in TGFβ-induced apoptosis in FaO hepatoma cells and suggests a distinct role for Smad3 [2].…”

Section: Introductionmentioning

confidence: 99%

“…Both early [5] and late activation of ROS in response to TGFB have been identified [10;11]. In lung fibroblasts, TGFβ induced NADH oxidase production of hydrogen peroxide begins 8 hours after treatment with peak activity at 16 hours [10].…”

Section: Introductionmentioning

confidence: 99%

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Transforming growth factor beta mediates hepatocyte apoptosis through Smad3 generation of reactive oxygen species

et al. 2007

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TGFβ induces hepatocyte apoptosis via reactive oxygen species (ROS) generation, the mitochondrial permeability transition (MPT), and caspase activation. The role of the Smad pathway in these events is unknown. In this study primary hepatocytes were isolated from Smad3 wild-type (+/+) and knockout (−/−) mice, and were treated with TGFβ (5 ng/ml) and/or trolox (2 mM). ROS generation, MPT, TGFβ-dependent transcription, and apoptosis were assessed in the presence or absence of Smad3 wild-type (WT) and dominant-negative (DN) plasmids. With TGFβ treatment, Smad3 (−/−) hepatocytes did not generate ROS activity, exhibit MPT, activate caspases, or undergo apoptosis when compared to Smad 3 (+/+) hepatocytes. Similarly, transfection of Smad3 (+/+) hepatocytes with DN-Smad3 inhibited TGFβ-mediated transcription, ROS generation, MPT, and apoptosis. However, Smad3 (−/−) cells transfected with WT-Smad3 and treated with TGFβ demonstrated increased transcriptional activity, the MPT, and TGFβ-induced apoptosis. TGFβ-mediated ROS generation occurred through an NADPH-like oxidase pathway since diphenyleneiodonium chloride inhibited ROS induction. In conclusion, TGFβ-induced hepatocyte apoptosis occurs through Smad3 dependent activation of ROS with subsequent activation of the MPT and caspases.

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Section: Mitochondrial Permeability Transition (Mpt)mentioning

confidence: 99%

“…Typically, TGFβ causes hepatocyte MPT prior to apoptosis [5]. In these experiments, MPT was assessed by confocal microscopy using the dyes TMRM and calcein.…”

Section: Smad3 (−/−) Hepatocytes Resist Tgfβ-induced Apoptosismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Transforming growth factor beta mediates hepatocyte apoptosis through Smad3 generation of reactive oxygen species

et al. 2007

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Murine cirrhosis induces hepatocyte epithelial mesenchymal transition and alterations in survival signaling pathways

et al. 2008

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Hepatocytes that reside in a chronically-injured liver have altered growth responses compared to hepatocytes in normal liver. Transforming growth factor beta (TGFβ) is upregulated in the cirrhotic liver, and cirrhotic hepatocytes, unlike normal hepatocytes exposed to this cytokine, exhibit decreased apoptosis. In fetal hepatocytes, TGFβ also induces epithelial-mesenchymal transition (EMT) and signaling changes in cell survival pathways. Here, chronic murine liver injury was induced by twice-weekly carbon tetrachloride administration for 8 weeks. Normal liver-derived hepatocytes (NLDH) and cirrhotic liver-derived hepatocytes (CLDH) were examined for EMT and the small mothers against decapentaplegic homolog (Smad), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen activated protein kinase (MAPK) pathways were investigated. Immunofluorescence imaging of cirrhotic livers demonstrated increased vimentin expression, which was confirmed by immunoblot analysis. In vitro, CLDH exhibited increased vimentin and type 1 collagen expression within cellular extensions consistent with EMT. Treatment with TGFβ augmented the EMT response in CLDH. In contrast, untreated NLDH did not display features of EMT but responded to TGFβ with increased vimentin expression and EMT characteristics. In response to PI3K/Akt inhibition, CLDH had decreased basal and insulin-stimulated p-Akt expression and decreased apoptosis compared to NLDH. In both NLDH and CLDH, vimentin expression was dependent on PI3K/Akt activity. CLDH demonstrated increased basal p-extracellular signal-regulated kinase expression that was independent of Smad and PI3K/Akt signaling. Inhibition of the MAPK pathway produced a marked increase in CLDH apoptosis. Conclusion: CLDH have increased vimentin and type 1 collagen expression and morphologic features consistent with EMT. In addition, compared to NLDH, the cellular signaling phenotype of CLDH changes from a MAPK-independent pathway to a MAPK-dependent cell survival pathway. These findings may have clinical implications for chemoprevention of hepatocellular carcinoma in the cirrhotic liver.

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A Transforming Growth Factor‐β and H19 Signaling Axis in Tumor‐Initiating Hepatocytes That Regulates Hepatic Carcinogenesis

et al. 2018

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Primary cirrhotic hepatocytes resist TGF$beta;-induced apoptosis through a ROS-dependent mechanism

Cited by 30 publications

References 54 publications

Transforming growth factor beta mediates hepatocyte apoptosis through Smad3 generation of reactive oxygen species

Transforming growth factor beta mediates hepatocyte apoptosis through Smad3 generation of reactive oxygen species

Murine cirrhosis induces hepatocyte epithelial mesenchymal transition and alterations in survival signaling pathways

A Transforming Growth Factor‐β and H19 Signaling Axis in Tumor‐Initiating Hepatocytes That Regulates Hepatic Carcinogenesis

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