Typically inhibiting USP14 promotes autophagy in M1-like macrophages and alleviates CLP-induced sepsis
CELL DEATH & DISEASE
Authors: Xu, Fang; Ma, Yuxiang; Huang, Wei; Gao, Jian; Guo, Mengmeng; Li, Jianxin; Kong, Lingdong; Liang, Guang; Du, Ronghui; Xu, Qiang; Wu, Xudong
Abstract
Macrophages, with diverse functions and variable phenotypes, are considered as an important executor of inflammatory diseases. And it has been proved that autophagy is deeply connected with the development of inflammation, while the exact regulatory mechanism still remains unclear, and the application of autophagy regulators in anti-inflammation needs to be further confirmed. Here, we firstly verified that neochromine S5 (hereinafter referred to as S5) significantly inhibited M1-like macrophage polarization with decrease of the proinflammatory cytokines and downregulation of NF-kappa B and STAT1 signals. Then, in vivo experiments demonstrated S5 improved cecal ligation and puncture (CLP)-induced sepsis specially based on the regulation of M1-like macrophages. Mechanistic studies indicated that S5 treatment dramatically upregulated cellular autophagy in M1-like macrophage. Furthermore, by multiple methods, S5 was revealed to directly bind with ubiquitin-specific proteases 14 (USP14) at Ser404, Phe405, and Cys414 by hydrogen bond to inhibit its deubiquitinating activity, and block USP14-TRAF6 (TNF receptor associated factor 6) interaction, subsequently promoting ubiquitination of Beclin1, interrupting Beclin1-Bcl2 interaction, and accumulating the autophagosome in macrophages, which finally resulted in the blockade of M1-like macrophage polarization. Animal experiments also confirmed the protection of S5 in CLP mice was dependent on activation of macrophage autophagy. What's more, as a novel USP14 inhibitor, S5 exhibited higher efficiency and safety than IU1, the known USP14 inhibitor. Therefore, this study has demonstrated that typically inhibiting USP14 promotes autophagy in M1-like macrophages and alleviates CLP-induced sepsis. Moreover, we provide a new candidate compound, S5, for sensitizing autophagy to interfere with the macrophage inflammation.
MNDA controls the expression of MCL-1 and BCL-2 in chronic lymphocytic leukemia cells
EXPERIMENTAL HEMATOLOGY
Authors: Bottardi, Stefania; Guieze, Romain; Bourgoin, Vincent; Fotouhi-Ardakani, Nasser; Douge, Aurore; Darracq, Anais; Lakehal, Yahia A.; Berger, Marc G.; Mollica, Luigina; Bay, Jacques-Olivier; Omichinski, James G.; Milot, Eric
Abstract
The myeloid nuclear differentiation antigen (MNDA) is a stress-induced protein that promotes degradation of the anti-apoptotic factor MCL-1 and apoptosis in myeloid cells. MNDA is also expressed in normal lymphoid cells and in B-cell clones isolated from individuals with chronic lymphocytic leukemia (CLL), a disease characterized by abnormal apoptosis control. We found that MNDA expression levels inversely correlate with the amount of the anti-apoptotic proteins MCL-1 and BCL-2 in human CLL sam-ples. We report that in response to chemotherapeutic agents that induce genotoxic stress, MNDA exits its typical nucleolar localization and accumulates in the nucleo-plasm of CLL and lymphoid cells. Then, MNDA binds chromatin at Mcl1 and Bcl2 genes and affects the transcriptional competence of RNA polymerase II. Our data also reveal that MNDA specifically associates with Mcl1 and Bcl2 (pre-) mRNAs and favors their rapid turnover as a prompt response to genotoxic stress. We propose that this rapid dynamic tuning of RNA levels, which leads to the destabilization of Mcl1 and Bcl2 transcripts, represents a post-transcriptional mechanism of apoptosis control in CLL cells. These results provide an explanation of previous clinical data and corrobo-rate the finding that higher MNDA expression levels in CLL are associated with a bet-ter clinical course. (c) 2020 Published by Elsevier Inc. on behalf of ISEH - Society for Hematology and Stem Cells. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)