scholarly journals Deacetylation of p53 induces autophagy by suppressing Bmf expression

2013 ◽  
Vol 201 (3) ◽  
pp. 427-437 ◽  
Author(s):  
Amelia U. Contreras ◽  
Yohannes Mebratu ◽  
Monica Delgado ◽  
Gilbert Montano ◽  
Chien-an A. Hu ◽  
...  

Interferon γ (IFN-γ)–induced cell death is mediated by the BH3-only domain protein, Bik, in a p53-independent manner. However, the effect of IFN-γ on p53 and how this affects autophagy have not been reported. The present study demonstrates that IFN-γ down-regulated expression of the BH3 domain-only protein, Bmf, in human and mouse airway epithelial cells in a p53-dependent manner. p53 also suppressed Bmf expression in response to other cell death–stimulating agents, including ultraviolet radiation and histone deacetylase inhibitors. IFN-γ did not affect Bmf messenger RNA half-life but increased nuclear p53 levels and the interaction of p53 with the Bmf promoter. IFN-γ–induced interaction of HDAC1 and p53 resulted in the deacetylation of p53 and suppression of Bmf expression independent of p53’s proline-rich domain. Suppression of Bmf facilitated IFN-γ–induced autophagy by reducing the interaction of Beclin-1 and Bcl-2. Furthermore, autophagy was prominent in cultured bmf−/− but not in bmf+/+ cells. Collectively, these observations show that deacetylation of p53 suppresses Bmf expression and facilitates autophagy.

1998 ◽  
Vol 274 (5) ◽  
pp. L864-L869 ◽  
Author(s):  
X. L. Yao ◽  
T. Ikezono ◽  
M. Cowan ◽  
C. Logun ◽  
C. W. Angus ◽  
...  

Clara cell secretory protein (CCSP) is an inhibitor of secretory phospholipase A2. It is produced by airway epithelial cells and is present in airway secretions. Because interferon (IFN)-γ can induce gene expression in airway epithelial cells and may modulate the inflammatory response in the airway, it was of interest to study the effect of this cytokine on epithelial cell CCSP mRNA expression and CCSP protein synthesis. A human bronchial epithelial cell line (BEAS-2B) was used for this study. CCSP mRNA was detected by ribonuclease protection assay. IFN-γ was found to increase CCSP mRNA expression in a time- and dose-dependent manner. The CCSP mRNA level increased after IFN-γ (300 U/ml) treatment for 8–36 h, with the peak increase at 18 h. Immunobloting of CCSP protein also demonstrated that IFN-γ induced the synthesis and secretion of CCSP protein in a time-dependent manner. Nuclear run-on, CCSP reporter gene activity assay, and CCSP mRNA half-life assay demonstrated that IFN-γ-induced increases in CCSP gene expression were mediated, at least in part, at the posttranscriptional level. The present study demonstrates that IFN-γ can induce increases in steady-state mRNA levels and protein synthesis of human CCSP protein in airway epithelial cells and may modulate airway inflammatory responses in this manner.


1999 ◽  
Vol 276 (3) ◽  
pp. C700-C710 ◽  
Author(s):  
Lisa M. Schwiebert ◽  
Kim Estell ◽  
Stacie M. Propst

To delineate the mechanisms that facilitate leukocyte migration into the cystic fibrosis (CF) lung, expression of chemokines, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and RANTES, was compared between CF and non-CF airway epithelia. The findings presented herein demonstrate that, under either basal conditions or tumor necrosis factor-α (TNF-α)- and/or interferon-γ (IFN-γ)-stimulated conditions, a consistent pattern of differences in the secretion of IL-8 and MCP-1 between CF and non-CF epithelial cells was not observed. In contrast, CF epithelial cells expressed no detectable RANTES protein or mRNA under basal conditions or when stimulated with TNF-α and/or IFN-γ ( P ≤ 0.05), unlike their non-CF counterparts. Correction of the CF transmembrane conductance regulator (CFTR) defect in CF airway epithelial cells restored the induction of RANTES protein and mRNA by TNF-α in combination with IFN-γ ( P ≤ 0.05) but had little effect on IL-8 or MCP-1 production compared with mock controls. Transfection studies utilizing RANTES promoter constructs suggested that CFTR activates the RANTES promoter via a nuclear factor-κB-mediated pathway. Together, these results suggest that 1) RANTES expression is altered in CF epithelia and 2) epithelial expression of RANTES, but not IL-8 or MCP-1, is dependent on CFTR.


2008 ◽  
Vol 183 (3) ◽  
pp. 429-439 ◽  
Author(s):  
Yohannes A. Mebratu ◽  
Burton F. Dickey ◽  
Chris Evans ◽  
Yohannes Tesfaigzi

IFNγ induces cell death in epithelial cells, but the mediator for this death pathway has not been identified. In this study, we find that expression of Bik/Blk/Nbk is increased in human airway epithelial cells (AECs [HAECs]) in response to IFNγ. Expression of Bik but not mutant BikL61G induces and loss of Bik suppresses IFNγ-induced cell death in HAECs. IFNγ treatment and Bik expression increase cathepsin B and D messenger RNA levels and reduce levels of phospho–extracellular regulated kinase 1/2 (ERK1/2) in the nuclei of bik+/+ compared with bik−/− murine AECs. Bik but not BikL61G interacts with and suppresses nuclear translocation of phospho-ERK1/2, and suppression of ERK1/2 activation inhibits IFNγ- and Bik-induced cell death. Furthermore, after prolonged exposure to allergen, hyperplastic epithelial cells persist longer, and nuclear phospho-ERK is more prevalent in airways of IFNγ−/− or bik−/− compared with wild-type mice. These results demonstrate that IFNγ requires Bik to suppress nuclear localization of phospho-ERK1/2 to channel cell death in AECs.


2002 ◽  
Vol 11 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Vera L. Petricevich

The purpose of this study was to investigate the effects ofTityus serrulatusvenom (TSV) on murine peritoneal macrophages evaluated in terms of activation. The effects of crude TSV were analysed by detection of cytokines, oxygen intermediate metabolites (H2O2) and nitric oxide (NO) in supernatants of peritoneal macrophages. Several functional bioassays were employed including anin vitromodel for envenomating: cytotoxicity of TSV was assessed using the lyses percentage. Tumor necrosis factor (TNF) activity was assayed by measuring its cytotoxic activity on L-929 cells, and interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay, whereas NO levels were detected by Griess colorimetric reactions in culture supernatant of macrophages incubated with TSV and subsequently exposed to either lipopolysaccharide or IFN-γ. Incubation of macrophages with TSV increased production of IL-6 and IFN-γ in a dose-dependent manner. TNF production was not detected in supernatants treated with TSV at any concentration. The increase in IL-6 secretion was not associated with concentration-dependent cytoxicity of TSV on these cells. These data suggest that the cytotoxicity does not appear to be the main cause of an increased cytokine production by these cells. Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate, ranging from 125 to 800 mM. Interestingly, NO levels of peritoneal macrophages were increased after IFN-γ. Moreover, NO production had an apparent effect on macrophage activity. The results obtained here also shown that the TSV induces an important elevation in H2O2release. These results combined with NO production suggest that TSV possesses significant immunomodulatory activities capable of stimulating immune functionsin vitro.


Blood ◽  
2001 ◽  
Vol 98 (2) ◽  
pp. 436-441 ◽  
Author(s):  
Fuminari Ishibashi ◽  
Tomoyuki Mizukami ◽  
Shiro Kanegasaki ◽  
Lena Motoda ◽  
Ryota Kakinuma ◽  
...  

Chronic granulomatous disease (CGD) is an inherited disorder of host defense against microbial infections caused by defective activity of the phagocyte NADPH oxidase. Based on an increase of neutrophil superoxide-generating ability in response to interferon γ (IFN-γ) in a single patient with CGD, multicentered group studies demonstrated a beneficial effect of prophylactic IFN-γ. However, no apparent increase of the phagocyte superoxide generation was found in patients enrolled in these studies. The present report offers an additional kindred in whom an IFN-γ–dependent increase in neutrophil superoxide production was observed in 3 affected patients. The defect in the CYBB gene for gp91-phox was identified as an otherwise silent mutation adjacent to the third intron of theCYBB gene that alters messenger RNA splicing. By molecular analysis, significant differences were found in the splicing pattern ofCYBB gene transcripts in patient neutrophils between 1 and 25 days after administration of IFN-γ. Furthermore, a complete transcript containing the missing exons could be detected in all specimens after the treatment. The changes in the splicing pattern of the transcripts and the prolonged effect on superoxide-generating ability of patient neutrophils indicate that IFN-γ induced a partial correction of the abnormal splicing of CYBB gene transcripts in myeloid progenitor cells.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Vasiliki Panagiotakopoulou ◽  
Dina Ivanyuk ◽  
Silvia De Cicco ◽  
Wadood Haq ◽  
Aleksandra Arsić ◽  
...  

Abstract Parkinson’s disease-associated kinase LRRK2 has been linked to IFN type II (IFN-γ) response in infections and to dopaminergic neuronal loss. However, whether and how LRRK2 synergizes with IFN-γ remains unclear. In this study, we employed dopaminergic neurons and microglia differentiated from patient-derived induced pluripotent stem cells carrying LRRK2 G2019S, the most common Parkinson’s disease-associated mutation. We show that IFN-γ enhances the LRRK2 G2019S-dependent negative regulation of AKT phosphorylation and NFAT activation, thereby increasing neuronal vulnerability to immune challenge. Mechanistically, LRRK2 G2019S suppresses NFAT translocation via calcium signaling and possibly through microtubule reorganization. In microglia, LRRK2 modulates cytokine production and the glycolytic switch in response to IFN-γ in an NFAT-independent manner. Activated LRRK2 G2019S microglia cause neurite shortening, indicating that LRRK2-driven immunological changes can be neurotoxic. We propose that synergistic LRRK2/IFN-γ activation serves as a potential link between inflammation and neurodegeneration in Parkinson’s disease.


Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2914-2923 ◽  
Author(s):  
Helena Spets ◽  
Patrik Georgii-Hemming ◽  
Jan Siljason ◽  
Kenneth Nilsson ◽  
Helena Jernberg-Wiklund

Abstract A poor response to Fas-induced apoptosis is evident in some multiple myeloma (MM) cell lines and primary cells. In this study, we have examined the possibility to increase the sensitivity to Fas-induced apoptosis by pretreatment of MM cells with interferon-γ (IFN-γ) or interferon- (IFN-). Both IFN-γ and IFN- markedly increased the Fas-induced apoptosis in all cell lines tested (U-266-1970, U-266-1984, and U-1958). In the U-266-1970 and U-1958 cell lines, pretreatment with either IFN-γ or IFN- also inhibited proliferation in a dose-dependent manner. In contrast, IFN-γ activation of the Fas death pathway in the U-266-1984 cells was not accompanied by growth inhibition. Incubation with the IFNs increased the Fas antigen expression in one of three cell lines but did not alter the expression of Bcl-2 or Bax. The IFNs are important regulators of growth and survival in MM cells. Our results suggest that activation of Fas-mediated apoptosis is a novel mechanism by which the IFNs exert inhibitory effects on MM cells. © 1998 by The American Society of Hematology.


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