TY  - JOUR
A1  - Jost, Priska
A1  - Klein, Franziska
A1  - Brand, Benjamin
A1  - Wahl, Vanessa
A1  - Wyatt, Amanda
A1  - Yildiz, Daniela
A1  - Boehm, Ulrich
A1  - Niemeyer, Barbara A.
A1  - Vaeth, Martin
A1  - Alansary, Dalia
T1  - Acute downregulation but not genetic ablation of murine MCU impairs suppressive capacity of regulatory CD4 T cells
JF  - International Journal of Molecular Sciences
N2  - By virtue of mitochondrial control of energy production, reactive oxygen species (ROS) generation, and maintenance of Ca\(^{2+}\) homeostasis, mitochondria play an essential role in modulating T cell function. The mitochondrial Ca\(^{2+}\) uniporter (MCU) is the pore-forming unit in the main protein complex mediating mitochondrial Ca\(^{2+}\) uptake. Recently, MCU has been shown to modulate Ca\(^{2+}\) signals at subcellular organellar interfaces, thus fine-tuning NFAT translocation and T cell activation. The mechanisms underlying this modulation and whether MCU has additional T cell subpopulation-specific effects remain elusive. However, mice with germline or tissue-specific ablation of Mcu did not show impaired T cell responses in vitro or in vivo, indicating that ‘chronic’ loss of MCU can be functionally compensated in lymphocytes. The current work aimed to specifically investigate whether and how MCU influences the suppressive potential of regulatory CD4 T cells (Treg). We show that, in contrast to genetic ablation, acute siRNA-mediated downregulation of Mcu in murine Tregs results in a significant reduction both in mitochondrial Ca\(^{2+}\) uptake and in the suppressive capacity of Tregs, while the ratios of Treg subpopulations and the expression of hallmark transcription factors were not affected. These findings suggest that permanent genetic inactivation of MCU may result in compensatory adaptive mechanisms, masking the effects on the suppressive capacity of Tregs.
KW  - mitochondrial calcium uniporter
KW  - regulatory T cells
KW  - suppressive capacity
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313621
SN  - 1422-0067
VL  - 24
IS  - 9
ER  - 
TY  - JOUR
A1  - Dammert, Marcel A.
A1  - Brägelmann, Johannes
A1  - Olsen, Rachelle R.
A1  - Böhm, Stefanie
A1  - Monhasery, Niloufar
A1  - Whitney, Christopher P.
A1  - Chalishazar, Milind D.
A1  - Tumbrink, Hannah L.
A1  - Guthrie, Matthew R.
A1  - Klein, Sebastian
A1  - Ireland, Abbie S.
A1  - Ryan, Jeremy
A1  - Schmitt, Anna
A1  - Marx, Annika
A1  - Ozretić, Luka
A1  - Castiglione, Roberta
A1  - Lorenz, Carina
A1  - Jachimowicz, Ron D.
A1  - Wolf, Elmar
A1  - Thomas, Roman K.
A1  - Poirier, John T.
A1  - Büttner, Reinhard
A1  - Sen, Triparna
A1  - Byers, Lauren A.
A1  - Reinhardt, H. Christian
A1  - Letai, Anthony
A1  - Oliver, Trudy G.
A1  - Sos, Martin L.
T1  - MYC paralog-dependent apoptotic priming orchestrates a spectrum of vulnerabilities in small cell lung cancer
JF  - Nature Communications
N2  - MYC paralogs are frequently activated in small cell lung cancer (SCLC) but represent poor drug targets. Thus, a detailed mapping of MYC-paralog-specific vulnerabilities may help to develop effective therapies for SCLC patients. Using a unique cellular CRISPR activation model, we uncover that, in contrast to MYCN and MYCL, MYC represses BCL2 transcription via interaction with MIZ1 and DNMT3a. The resulting lack of BCL2 expression promotes sensitivity to cell cycle control inhibition and dependency on MCL1. Furthermore, MYC activation leads to heightened apoptotic priming, intrinsic genotoxic stress and susceptibility to DNA damage checkpoint inhibitors. Finally, combined AURK and CHK1 inhibition substantially prolongs the survival of mice bearing MYC-driven SCLC beyond that of combination chemotherapy. These analyses uncover MYC-paralog-specific regulation of the apoptotic machinery with implications for genotype-based selection of targeted therapeutics in SCLC patients.
KW  - genetic engineering
KW  - oncogenes
KW  - small-cell lung cancer
KW  - targeted therapies
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-223569
VL  - 10
ER  -