TY - JOUR TI - Malat1 regulates PMN-MDSC expansion and immunosuppression through p-STAT3 ubiquitination in sepsis AV - public Y1 - 2024/// EP - 1546 KW - Experimental sepsis KW - Polymorphonuclear myeloid-derived suppressor cell KW - Malat1 KW - STAT3 pathway KW - Ubiquitination N2 - Myeloid-derived suppressor cells (MDSCs) expand during sepsis and contribute to the development of persistent inflammation-immunosuppression-catabolism syndrome. However, the underlying mechanism remains unclear. Exploring the mechanisms of MDSCs generation may provide therapeutic targets for improving immune status in sepsis. Here, a sepsis mouse model is established by cecal ligation and perforation. Bone marrow cells at different sepsis time points are harvested to detect the proportion of MDSCs and search for differentially expressed genes by RNA-sequence. In lethal models of sepsis, polymorphonuclear-MDSCs (PMN-MDSCs) decrease in early but increase and become activated in late sepsis, which is contrary to the expression of metastasis-associated lung adenocarcinoma transcript 1 (Malat1). In vivo, Malat1 inhibitor significantly increases the mortality in mice with late sepsis. And in vitro, Malat1 down-regulation increases the proportion of PMN-MDSCs and enhanced its immunosuppressive ability. Mechanistically, Malat1 limits the differentiation of PMN-MDSCs by accelerating the degradation of phosphorylated STAT3. Furthermore, Stattic, an inhibitor of STAT3 phosphorylation, improves the survival of septic mice by inhibiting PMN-MDSCs. Overall, the study identifies a novel insight into the mechanism of sepsis-induced MDSCs and provides more evidence for targeting MDSCs in the treatment of sepsis. ID - discovery10187631 PB - Ivyspring International Publisher IS - 4 N1 - ©2024 Ivyspring International Publisher. This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). SP - 1529 VL - 20 JF - International Journal of Biological Sciences A1 - Wang, Yaodong A1 - Zhang, Caiyan A1 - Liu, Tingyan A1 - Yu, Zhenhao A1 - Wang, Kexin A1 - Ying, Jiayun A1 - Wang, Yao A1 - Zhu, Ting A1 - Li, Jingjing A1 - Hu, Xiuchuan Lucas A1 - Zhou, Yufeng A1 - Lu, Guoping UR - http://dx.doi.org/10.7150/ijbs.92267 ER -