TY - JOUR
T1 - The transcription factor ETS1 promotes apoptosis resistance of senescent cholangiocytes by epigenetically up-regulating the apoptosis suppressor BCL2L1
AU - O'Hara, Steven P.
AU - Splinter, Patrick L.
AU - Trussoni, Christy E.
AU - Guicciardi, Maria Eugenia
AU - Splinter, Noah P.
AU - Al Suraih, Mohammed S.
AU - Nasser-Ghodsi, Navine
AU - Stollenwerk, Deborah
AU - Gores, Gregory J.
AU - LaRusso, Nicholas F.
N1 - Funding Information:
This work was supported by National Institutes of Health Grant DK57993 (to N. F. L), the Mayo Foundation, the Clinical and Optical Microscopy Cores of the Mayo Clinic Center for Cell Signaling in Gastroenterology Grant P30DK084567, and The Chris M. Carlos and Catharine Nicole Jockisch Car-los Endowment Fund in Primary Sclerosing Cholangitis (PSC). The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Funding Information:
This work was supported by National Institutes of Health Grant DK57993 (to N. F. L), the Mayo Foundation, the Clinical and Optical Microscopy Cores of the Mayo Clinic Center for Cell Signaling in Gastroenterology Grant P30DK084567, and The Chris M. Carlos and Catharine Nicole Jockisch Carlos Endowment Fund in Primary Sclerosing Cholangitis (PSC). The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Publisher Copyright:
© 2019 O'Hara et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2019/12/6
Y1 - 2019/12/6
N2 - Primary sclerosing cholangitis (PSC) is an idiopathic, progressive cholangiopathy. Cholangiocyte senescence is important in PSC pathogenesis, and we have previously reported that senescence is regulated by the transcription factor ETS protooncogene 1 (ETS1) and associated with overexpression of BCL2 like 1 (BCL2L1 or BCL-xL), an anti-apoptotic BCL2-family member. Here, we further explored the mechanisms regulating BCL-xL-mediated, apoptosis resistance in senescent cholangiocytes and uncovered that ETS1 and the histone acetyltransferase E1A-binding protein P300 (EP300 or p300) both promote BCL-xL transcription. Using immunofluorescence, we found that BCL-xL protein expression is increased both in cholangiocytes of livers from individuals with PSC and a mouse model of PSC. Using an in vitro model of lipopolysaccharide-induced senescence in normal human cholangiocytes (NHCs), we found increased BCL-xL mRNA and protein levels, and ChIP-PCRs indicated increased occupancy of ETS1, p300, and histone 3 Lys-27 acetylation (H3K27Ac) at the BCL-xL promoter. Using co-immunoprecipitation and proximity ligation assays, we further demonstrate that ETS1 and p300 physically interact in senescent but not control NHCs. Additionally, mutagenesis of predicted ETS1-binding sites within the BCL-xL promoter blocked luciferase reporter activity, and CRISPR/Cas9-mediated genetic deletion of ETS1 reduced senescence-associated BCL-xL expression. In senescent NHCs, TRAIL-mediated apoptosis was reduced ~70%, and ETS1 deletion or RNAi-mediated BCL-xL suppression increased apoptosis. Overall, our results suggest that ETS1 and p300 promote senescent cholangiocyte resistance to apoptosis by modifying chromatin and inducing BCL-xL expression. These findings reveal ETS1 as a central regulator of both cholangiocyte senescence and the associated apoptosis-resistant phenotype.
AB - Primary sclerosing cholangitis (PSC) is an idiopathic, progressive cholangiopathy. Cholangiocyte senescence is important in PSC pathogenesis, and we have previously reported that senescence is regulated by the transcription factor ETS protooncogene 1 (ETS1) and associated with overexpression of BCL2 like 1 (BCL2L1 or BCL-xL), an anti-apoptotic BCL2-family member. Here, we further explored the mechanisms regulating BCL-xL-mediated, apoptosis resistance in senescent cholangiocytes and uncovered that ETS1 and the histone acetyltransferase E1A-binding protein P300 (EP300 or p300) both promote BCL-xL transcription. Using immunofluorescence, we found that BCL-xL protein expression is increased both in cholangiocytes of livers from individuals with PSC and a mouse model of PSC. Using an in vitro model of lipopolysaccharide-induced senescence in normal human cholangiocytes (NHCs), we found increased BCL-xL mRNA and protein levels, and ChIP-PCRs indicated increased occupancy of ETS1, p300, and histone 3 Lys-27 acetylation (H3K27Ac) at the BCL-xL promoter. Using co-immunoprecipitation and proximity ligation assays, we further demonstrate that ETS1 and p300 physically interact in senescent but not control NHCs. Additionally, mutagenesis of predicted ETS1-binding sites within the BCL-xL promoter blocked luciferase reporter activity, and CRISPR/Cas9-mediated genetic deletion of ETS1 reduced senescence-associated BCL-xL expression. In senescent NHCs, TRAIL-mediated apoptosis was reduced ~70%, and ETS1 deletion or RNAi-mediated BCL-xL suppression increased apoptosis. Overall, our results suggest that ETS1 and p300 promote senescent cholangiocyte resistance to apoptosis by modifying chromatin and inducing BCL-xL expression. These findings reveal ETS1 as a central regulator of both cholangiocyte senescence and the associated apoptosis-resistant phenotype.
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U2 - 10.1074/jbc.RA119.010176
DO - 10.1074/jbc.RA119.010176
M3 - Article
C2 - 31659122
AN - SCOPUS:85076325559
SN - 0021-9258
VL - 294
SP - 18698
EP - 18713
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 49
ER -