Correction: Multi-Scale In Vivo Systems Analysis Reveals the Influence of Immune Cells on TNF-α-Induced Apoptosis in the Intestinal Epithelium

ABSTRACT Several reports have linked activating protein 2α (AP-2α) to apoptosis, leading us to hypothesize that AP-2α is a substrate for caspases. We tested this hypothesis by examining the effects of tumor necrosis factor alpha (TNF-α) on the expression of AP-2 in breast cancer cells. Here, we provide evidence that TNF-α downregulates AP-2α and AP-2γ expression posttranscriptionally during TNF-α-induced apoptosis. Both a general caspase antagonist (zVADfmk) and a caspase 6-preferred antagonist (zVEIDfmk) inhibited TNF-α-induced apoptosis and AP-2α downregulation. In vivo tests showed that AP-2α was cleaved by caspases ahead of the DNA fragmentation phase of apoptosis. Recombinant caspase 6 cleaved AP-2α preferentially, although caspases 1 and 3 also cleaved it, albeit at 50-fold or higher concentrations. Activated caspase 6 was detected in TNF-α-treated cells, thus confirming its involvement in AP-2α cleavage. All three caspases cleaved AP-2α at asp19 of the sequence asp-arg-his-asp (DRHD19). Mutating D19 to A19abrogated AP-2α cleavage by all three caspases. TNF-α-induced cleavage of AP-2α in vivo led to AP-2α degradation and loss of DNA-binding activity, both of which were prevented by pretreatment with zVEIDfmk. AP-2α degradation but not cleavage was inhibited in vivo by PS-431 (a proteasome antagonist), suggesting that AP-2α is degraded subsequent to cleavage by caspase 6 or caspase 6-like enzymes. Cells transfected with green fluorescent protein-tagged mutant AP-2α are resistant to TNF-α-induced apoptosis, further demonstrating the link between caspase-mediated cleavage of AP-2α and apoptosis. This is the first report to demonstrate that degradation of AP-2α is a critical event in TNF-α-induced apoptosis. Since the DRHD sequence in vertebrate AP-2 is widely conserved, its cleavage by caspases may represent an important mechanism for regulating cell survival, proliferation, differentiation, and apoptosis.

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P-165 Cytometry-Based Single Cell Analysis of Intact Epithelial Signaling Reveals MAPK Activation Divergent from TNF-α-Induced Apoptosis in Vivo

Inflammatory Bowel Diseases ◽

10.1097/01.mib.0000480283.46656.d8 ◽

2016 ◽

Vol 22 ◽

pp. S59-S60

Author(s):

Alan Simmons ◽

Amrita Banerjee ◽

Eliot McKinley ◽

Cherieʼ Scurrah ◽

Jeffrey Franklin ◽

...

Keyword(s):

Single Cell ◽

Single Cell Analysis ◽

Cell Analysis ◽

Mapk Activation ◽

Tnf Α ◽

Induced Apoptosis

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Differential protective effects of Bcl-xL and Bcl-2 on apoptotic liver injury in transgenic mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1999.277.3.g702 ◽

1999 ◽

Vol 277 (3) ◽

pp. G702-G708 ◽

Cited By ~ 12

Author(s):

Alix de la Coste ◽

Monique Fabre ◽

Nathalie McDonell ◽

Arlette Porteu ◽

Helène Gilgenkrantz ◽

...

Keyword(s):

Liver Injury ◽

Transgenic Mice ◽

Fas Ligand ◽

Dependent Manner ◽

Protective Effects ◽

Tnf Α ◽

Apoptotic Pathways ◽

Induced Apoptosis ◽

Factor Α

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.

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Knockdown of miR-660 protects nucleus pulposus cells from TNF-a-induced apoptosis by targeting serum amyloid A1

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-019-1538-6 ◽

2020 ◽

Vol 15 (1) ◽

Cited By ~ 2

Author(s):

Hao Jie Zhang ◽

Xue Hai Ma ◽

Song Lin Xie ◽

Shu lian Qin ◽

Cong Zhi Liu ◽

...

Keyword(s):

Nucleus Pulposus ◽

General Characteristic ◽

Luciferase Reporter ◽

Healthy Controls ◽

Nucleus Pulposus Cells ◽

Apoptosis Rate ◽

Tnf Α ◽

Significant Difference ◽

Induced Apoptosis

Abstract Background Intervertebral disc degeneration (IVDD) is a well-known cause of lower back pain, which is induced by multiple factors including increased apoptosis and decreased survival of nucleus pulposus cells. In this study, we evaluate the effect and potential mechanism of miR-660 on the nucleus pulposus cells apoptosis induced by TNF-α. Methods First, we collected tissue of nucleus pulposus from IVDD and healthy controls. General characteristic of the IVDD and healthy control was also collected. And, we also collected nucleus pulposus cells that stimulated by TNF-α or control. miRNA microarray was performed to identify the differentially expressed miRNAs. Apoptosis rate and miR-660 relative expression was measured after stimulated with different concentration of TNF-α to identify the optimal concentration of TNF-α. Second, we successfully constructed antigomiR-660 to block the miR-660 expression in nucleus pulposus cells and then stimulated with TNF-α (100 ng/ml, 12 h). The apoptosis rates and relative protein expression were then measured again. The target association between miR-660 and SAA1 was confirmed by dual-luciferase reporter. Results There was no significant difference between the age (IVDD: 39 ± 10 years, healthy controls: 36 ± 7 years), BMI and sex between IVDD and healthy controls. Microarray analysis found that miR-660 was significantly up-regulated in IVDD and TNF-α treated groups, which was further identified by PCR. We found that the rate of apoptosis and miR-660 expression increased with TNF-α concentration increased. Finally, TNF-a with 100 ng/ml was used for further experiment. Compared with TNF-α group, TNF-α + antigomiR-660 could significantly down-regulated the apoptosis rate and relative protein (c-Caspase3 and c-Caspase7). Dual-luciferase reporter revealed that miR-660 could directly binding to the SAA1 at 80–87 sites. Compared with TNF-α alone group, TNF-α + antigomiR-660 significantly up-regulated the SAA1 expression (P < 0.05). Conclusion These results indicated that knockdown of miR-660 protected the nucleus pulposus from apoptosis that induced TNF-α via up-regulation of SAA1. Further studies should focus on the role of miR-660 in protecting IVDD in vivo.

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BCL-W expression is an important determinant of damage-induced apoptosis in murine small and large intestinal epithelium in vivo

Gastroenterology ◽

10.1016/s0016-5085(00)84284-5 ◽

2000 ◽

Vol 118 (4) ◽

pp. A538

Author(s):

David M. Pritchard ◽

Cristin Print ◽

Jerry M. Adams ◽

Christopher S. Potten ◽

John A. Hickman

Keyword(s):

Intestinal Epithelium ◽

Important Determinant ◽

Induced Apoptosis

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Apoptotic Effects of LPS on Fibroblasts are Indirectly Mediated through TNFR1

Journal of Dental Research ◽

10.1177/154405910408300903 ◽

2004 ◽

Vol 83 (9) ◽

pp. 671-676 ◽

Cited By ~ 23

Author(s):

M. Alikhani ◽

Z. Alikhani ◽

D.T. Graves

Keyword(s):

Tnf Receptor ◽

In Vivo Experiments ◽

Tnf Α ◽

Apoptotic Genes ◽

Induced Apoptosis ◽

Apoptotic Effects ◽

Periodontal Attachment Loss ◽

Fibroblastic Cells ◽

Subcutaneous Inoculation

During periods of periodontal attachment loss, one of the most significant cellular changes is a decrease in the number of fibroblasts. We previously demonstrated that LPS induces apoptosis of fibroblastic cells in vivo, largely through TNF-α. We conducted in vivo experiments by subcutaneous inoculation of LPS in wild-type, TNFR1−/−R2−/−, TNFR1−/−, and TNFR2−/− mice to identify which TNF receptors are involved and the specific caspase pathway activated. LPS stimulated apoptosis through TNFR1 but not TNFR2, which was accompanied by the induced expression of 12 apoptotic genes. Fluorometric studies demonstrated that LPS in vivo significantly increased caspase-8 and caspase-3 activity, which was also dependent on TNF receptor signaling. By the use of specific caspase inhibitors, caspases-3 and -8 were shown to play an important role in LPS-induced apoptosis in vivo. Thus, LPS acts through TNFR1 to modulate the expression of apoptotic genes and activate caspases-3 and -8.

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Engeletin Protects Against TNF-α-Induced Apoptosis and Reactive Oxygen Species Generation in Chondrocytes and Alleviates Osteoarthritis in vivo

Journal of Inflammation Research ◽

10.2147/jir.s297166 ◽

2021 ◽

Vol Volume 14 ◽

pp. 745-760

Author(s):

Hao Wang ◽

Zengxin Jiang ◽

Zhiying Pang ◽

Guobin Qi ◽

Bingxuan Hua ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Reactive Oxygen Species Generation ◽

Reactive Oxygen ◽

Oxygen Species ◽

Tnf Α ◽

Induced Apoptosis

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Modulatory effects of ozone on THP-1 cells in response to SP-A stimulation

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00125.2004 ◽

2005 ◽

Vol 288 (2) ◽

pp. L317-L325 ◽

Cited By ~ 26

Author(s):

Branislava Janic ◽

Todd M. Umstead ◽

David S. Phelps ◽

Joanna Floros

Keyword(s):

Immune Cells ◽

Cytokine Production ◽

Cell Damage ◽

Surfactant Protein ◽

Proinflammatory Cytokine Production ◽

Tnf Α ◽

In Vitro Systems ◽

Alveolar Proteinosis

Ozone (O3), a major component of air pollution and a strong oxidizing agent, can lead to lung injury associated with edema, inflammation, and epithelial cell damage. The effects of O3on pulmonary immune cells have been studied in various in vivo and in vitro systems. We have shown previously that O3exposure of surfactant protein (SP)-A decreases its ability to modulate proinflammatory cytokine production by cells of monocyte/macrophage lineage (THP-1 cells). In this report, we exposed THP-1 cells and/or native SP-A obtained from bronchoalveolar lavage of patients with alveolar proteinosis to O3and studied cytokine production and NF-κB signaling. The results showed 1) exposure of THP-1 cells to O3significantly decreased their ability to express TNF-α in response to SP-A; TNF-α production, under these conditions, was still significantly higher than basal (unstimulated) levels in filtered air-exposed THP-1 cells; 2) exposure of both THP-1 cells and SP-A to O3did not result in any significant differences in TNF-α expression compared with basal levels; 3) O3exposure of SP-A resulted in a decreased ability of SP-A to activate the NF-κB pathway, as assessed by the lack of significant increase and decrease of the nuclear p65 subunit of NF-κB and cytoplasmic IκBα, respectively; and 4) O3exposure of THP-1 cells resulted in a decrease in SP-A-mediated THP-1 cell responsiveness, which did not seem to be mediated via the classic NF-κB pathway. These findings indicate that O3exposure may mediate its effect on macrophage function both directly and indirectly (via SP-A oxidation) and by involving different mechanisms.

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